MLT Basic Chemistry
Diploma MLT Basic Chemistry HSBTE
Dr Pramila Singh
5/28/202328 min read
UNIT I
Biologically important elements, the study of their atomic number, mass number, atomic mass, equivalent weight & molecular weight.
Biological important elements are also called essential elements. They are chemical elements essential for living organisms to perform various physiological functions. These elements are required for the living organism's growth, development and survival. The following are some examples of biologically important elements.
1. Carbon (C): Carbon is the backbone of organic molecules Such as carbohydrates, lipids, proteins and nucleic acid. These are essential compounds for cell structure and function.
· Atomic No 6
Mass No 12 (6 proton and 6 Neutron)
Atomic mass (Molar mass): Approximately 12.01 g/mol. It is the average mass of carbon’s naturally occurring isotopes.
Equivalent Weight (gram equivalent mass). It depends on the reaction and valency of carbon in a specific reaction.
Molecular weight: The molecular weight of carbon varies depending on the composition of the molecule.
2. Hydrogen (H): Hydrogen is a component of water and many organic compounds. It is required for the energy transfer and pH regulation.
Atomic No: 1
Mass No: There are three isotopes of hydrogen.
Mass No hydrogen-1 (Protium): 1, hydrogen-2 (deuterium): 2 (1 proton 1 neutron), Hydrogen-3 (tritium): 3 (1 proton, 2 neutrons).
Atomic mass (Molar mass): Approximately 1.008 of hydrogen-1. Hydrogen-1 is the most abundant hydrogen
Equivalent Weight (gram equivalent mass). 1.008
Molecular weight: 2.016
3. Oxygen (O): Oxygen is utilised by the cells to produce energy from glucose. It is also a component of water and several organic compounds.
Atomic No: 8
Mass No: Approximately 16
Atomic mass (Molar mass): Approximately 15.9994
Equivalent Weight (gram equivalent mass).
Molecular weight: 32
4. Nitrogen (N): Nitrogen is a component of proteins and nucleic acid. It plays an important role in protein synthesis and genetic coding
Atomic No: 7
Mass No: Approximately 14
Atomic mass (Molar mass): Approximately 14.007
Equivalent Weight (gram equivalent mass). Nitrogen equivalent weight depends upon the reaction.
Molecular weight: 28.014. (Sum of atomic masses of two nitrogen atoms).
5. Phosphorous (P): Phosphorous is a component of nucleic acid such as DNA and RNA. It is used in the formation of high-energy molecules such as ATP. ATP is a primary energy carrier in cells.
Atomic No: 15
Mass No: Approximately 31
Atomic mass (Molar mass): Approximately 30.974
Equivalent Weight (gram equivalent mass). 30.974
Molecular weight: The molecular weight of phosphorous depends upon a specific compound.
6. Sulphur (S): Sulphur is present in some amino acids. These amino acids are critical for the structure and function of the proteins
Atomic No: 16
Mass No: Approximately 32
Atomic mass (Molar mass): Approximately 32.06
Equivalent Weight (gram equivalent mass). 16.03
Molecular weight: 256.48.
7. Potassium (K), Sodium (Na), Calcium (Ca) and Magnesium (Mg): These are essential elements also called electrolytes. They play a crucial role in nerve function, muscle contraction, and maintaining body fluid balance.
8. Iron (Fe): Iron is a component of haemoglobin in red blood cells. They carry oxygen and carbon dioxide inside living organisms.
Atomic No: 26
Mass No: Approximately 56
Atomic mass (Molar mass): Approximately 55.845
Equivalent Weight (gram equivalent mass). 27.9225
Molecular weight: 55.845
9. Zinc (Zn): Zinc is a cofactor for many enzymes that participates in several biological reactions, DNA synthesis and immune functions.
Atomic No: 30
Mass No: Approximately 64
Atomic mass (Molar mass): Approximately 65.38
Equivalent Weight (gram equivalent mass). The equivalent weight of zinc depends upon the nature of the reaction.
Molecular weight: Zinc is an atom, not a molecule. It does not have molecular weight.
10. Copper (Cu): Copper is necessary for iron metabolism, antioxidant defence and synthesis of connective tissues.
Atomic No: 29
Mass No: Approximately 63.546
Atomic mass (Molar mass): Approximately 63.546
Equivalent Weight (gram equivalent mass). 31.773
Molecular weight: 63.546
11. Manganese (Mn): Manganese participates in various enzymatic reactions. It plays an important role in bone formation.
· Atomic No: 25
Mass No: Approximately 55 and 54
Atomic mass (Molar mass): Approximately 54.94
Equivalent Weight (gram equivalent mass). 27.47
Molecular weight: 86.94
12. Molybdenum: It is a cofactor for certain enzymes. It is involved in nitrogen metabolism.
Atomic No: 42
Mass No: Approximately 98
Atomic mass (Molar mass): Approximately 95.95
Equivalent Weight (gram equivalent mass). Equivalent weight depends upon a specific chemical reaction.
Molecular weight: Molybdenum is an element; It does not have molecular weight.
Importance of Basic chemistry in medical laboratory technology.
Basic chemistry is the backbone of medical laboratory technology. It helps in accurate diagnosis and understanding of diseases. It helps in research and medical advancement. This improves patient care and patient outcomes. Basic chemistry importance in medical laboratory technology can be explained as per the below details
Diagnostic test: Most Diagnostic tests under medical laboratory technology depend upon chemical analysis of the sample.
Reagent preparations: Reagents medical laboratory consists of chemicals. Knowledge of basic chemistry helps to understand the chemical properties of reagents.
Understanding of human body Physiology: Knowledge of basic chemistry helps medical laboratory professionals to understand chemical processes inside the human body.
Quality control: Knowledge of basic chemistry helps medical laboratory professionals to maintain quality control measures. This assures reliable and accurate results of tests.
Toxicology: Knowledge of basic chemistry helps medical laboratory professionals to identify and measure toxic substances in a patient’s sample.
Research and development: Knowledge of basic chemistry helps medical laboratory professionals to develop new medical technologies and diagnostic methods.
Immunology and serology: Knowledge of basic chemistry helps medical laboratory professionals to detect antigens and antibodies in the patient sample.
Haematology: Knowledge of basic chemistry helps medical laboratory professionals to study blood components and other parameters related to blood.
Safety measures: Chemicals are harmful to humans. Knowledge of chemicals helps medical laboratory professionals to protect from chemical harmful effects.
Importance of Water quality and glasswares in clinical laboratory: different types of glassware’s, use, cleaning, standardization of volumetric glassware & maintenance. Pipettes - various types and different pipetting techniques.
Importance of Water quality and Glass wares in clinical laboratory:
Importance of Water quality in clinical laboratory: Maintaining water quality in clinical laboratory is essential for accurate and reliable test results, proper functioning of equipments and to ensure best possible patient care. Water quality importance can be explained as per below details:
1. Accuracy of tests: Water is considered as universal solvent. It is used in several laboratory procedures such as reagent preparation, sample dilution, etc. Quality water is free from impurities. It does not interfere in laboratory tests. Quality water such as distilled water leads to accurate diagnosis and tests.
2. Reagent preparation: Reagents require distilled water to ensure effectiveness and quality of reagent. Normal water may contain contaminants that affect the composition of reagents and their effectiveness.
3. Equipment maintenance: High quality water shall be required to clean laboratory equipments. This cleaning prevents contamination. It also ensure accurate result of tests.
4. Reproducibility: Quality water ensure reproducibility of experiments and tests.
Thus, water quality directly affects accuracy of report, reliability of report and validity of diagnostic tests.
Importance of Glass wares in clinical laboratory: Glass wares are transparent, inert, and easy to sterilise. Thus they are ideal to measure liquids, to prepare solution and to conduct experiments. The followings are importance of glass wares in clinical laboratories:
1. Physical properties: Glass wares are transparent and non reactive to most of the reagents and temperature changes. Thus it is most suitable liquids accurately and to perform chemical reactions.
2. Shapes and sizes: Glass wares are available in different shapes and sizes. Thus, they are most suitable for clinical laboratories.
3. Accuracy: Glass wares measure liquid accurately. This ensures reliability of results.
4. Compatibility: Glass wares are inert and resistant to most of the chemicals. It does not contaminate the sample and reagents. It does not interfere during reaction and storage.
5. Transparency: Glass wares are transparent. This reactions, colour changes etc can be observed.
6. Heat resistant: Glass wares tolerate high temperature. Thus it is suitable for sterilisation, evaporation, and boiling of sample or reagent.
7. Ease of cleaning: Glass wares are easy to clean. Thus it does not contaminate the sample or reagent during storage or diagnostic test.
8. Sample storage: Glass wares are non reactive. Thus they are most suitable to store reagents.
9. Longevity: Glass wares have long life span if they are handled carefully.
10. Environmental friendly.
Different types of glassware’s, use: Several types of glass wares are used in clinical laboratories. They are designed for the specific purposes. The followings are the some examples of glass wares and their uses:
1. Beakers: They are cylindrical containers with flat bottom and a spout. Their capacitoes vary from 5 mL to 5000 mL. They are used to mix, to heat and to hold liquids. They are not suitable to measure liquid volume accurately.
2. Flasks: The capacity of flask may vary from 25 mL to 5000 mL. The followings are the types of flasks
· Conical flasks (Erlenmeyer flask): They are cone shaped with narrow neck. They are used to mix, to heat, and to store liquid. Its conical shape allows easy mixing of liquids without splashing.
· Flat bottom round flasks: They are mainly used to heat liquid.
· Round bottom flask: They are mainly used to be heated in a naked flame or in a electrothermal mentle.
· Volumetric flask: They are pear shaped flat bottomed with narrow long neck. Neck has marking that indicates capacity of volumetric flask. Neck is fitted with stopper. They are used to make volume of liquid accurately.
3. Test tubes: They are cylindrical container open at one end. They are used to hold small volume of liquid and to heat them.
4. Watch Glass: They are circular concave shaped piece of glass. They are used to cover beaker mouth. They are also used as surface for evaporation or crystallisation.
5. Petridish: They are circular, shallow dish with lid. They are used to hold culture media, to grow microorganism in culture media and to observe microorganism colony.
6. Funnel: They helps to separate solids from liquid or liquid from liquid or to pour liquid, chemicals and solutions into container.
7. Condenser: They are glass tube with cooling coil. They are used to condense vapour into liquid.
8. Desiccator: They are sealed container with drying agent. They are used to store chemicals sensitive to moisture.
9. Graduate cylinder (Measuring cylinder): They are toll narrow container. They have marking on their wall. They are used to measure volume of liquid. They are not as accurate as pipettes.
10. Burettes: They are long graduated tube with stopcock. They are used to transfer liqids accurately during analysis or titration.
11. Pipettes: They are used to transfer accurate volume of liquid. Pipettes may be micropipettes and volumetric pipettes. Micropipettes are used to transfer liquid in micro litre. Volumetric
12. pipettes are used to transfer liquid in millilitres. There are following five types of pipettes
· Graduated pipettes: They are available from 0.1 to 10 ml capacities.
· Serological pipettes: They are marked upto the tip. They are used to transfer regaents, blood, serum, plasma, etc.
· Mohar pipettes: They are graduated above tip. They are used as serological pipette.
· Volumetric pipettes: They are used to transfer liquid of its full capacity.
· Pasteur pipettes: They are used to separate plasma and serum from cells.
Cleaning of glass wares: Cleaning of glass wares is essential step for reliable laboratory test report. The following guide lines are followed to clean glass wares.
1. Pre rinsing: Rinse the glass ware immediately after use. Rinse the glass wares suitable liquids that can dissolve the contents of container. For example water, acetone etc.
2. Soaking: Soaking is used to remove stubborn residues on glass container wall. Cleaning solution such as mild detergent solutions, enzymatic cleaners, acid base solution are used in soaking step.
3. Brushing: Soft brush or scrub is used to remove contents from outer and inner wall of the container soaked in soaking solution.
4. Rinsing: Rinse the glass ware thoroughly with purified water. This remave the trace of cleaning agents present on the wall of containers. Repeat the rinsing multiple times.
5. Drying: Allow the glass ware to dry in air after rinsing. Sometimes oven at low temperature is used to dry glass wares.
Precautions: Avoid use of hard scrub or brush, acid cleaning agent, and scratching on glass ware wall.
Standardization of volumetric glassware: Standerdisation of volumetric glasswares is done to ensure accuracy of glasswares. Volumetric glassware, such as volumetric flasks, pipettes, and burettes, are used to measure volumes of liquids in laboratory.
Volumetric glasswares are staderdised as per below
1. Volumetric flask: Volumetric flask is used to prepare solutions with accuracy. Volumetric flask is standerdised by using solution of known concentration. Solution is added upto calibration mark on the neck of volumetric flask. Mass of solution and density of solution are used to calculate volume of solution in the volumetric flask.
2. Ppette: Pipette is used to transfer accurate volume of liquid. Solution of known concentration is drawn into pipette. Solution is transferred into a container. It volume or mass is measured. Difference between initial mass and final mass or volume gives accuracy of the pipette.
3. Pipette: Burette is used to deliver known volume of liquid during titration. Solution of known concentration is added into burette. Initial volume of liquid in burette is noted. Solution is allowed to drain out from burette into container until endpoint of titration. Difference between initial volume and final volume in burette indicates volume of liquid delivered by the burette.
Maintenance of volumetric glassware: Maintenance of volumetric glass wares in the clinical laboratory ensures accuracy and reliability of measurements of chemicals and reagents. The volumetric glass wares are maintained in the clinical laboratory as per below
1. Cleaning: Regular cleaning of glass wares prevents contamination and ensure accurate measurement. Mild detergent or specialised glassware cleaner with deionised water are used to clean glass wares. After cleaning rinse the glass wares using deionised water to remove any residue.
2. Drying: Allow glass wares to dry in air or in oven at low temperature. Avoid cloth or paper or towel to dry interior part of glass wares.
3. Calibration: Volumetric glass wares of calibration marks. It indicates volume of contents in the volumetric glass wares. Check this mark regularly using reference standards. If require, recalibrate.
4. Record keeping: Maintain proper record of date of calibration. This helps to know the reliability of volumetric glass wares.
5. Regular inspection: Regularly inspect the volumetric glass wares for damage such as cracks, scratches, etc.
6. Storage: Store volumetric glass wares in a clean and dust free area. Use protective caps to prevent entry of dust or contamination into volumetric glass wares.
7. Handling: Handle volumetric glass wares with great care and caution. Hold it by the appropriate part of volumetric glass wares such as neck of the flask.
8. Temperature: volumetric glass wares expand or contract with temperature changes. Allow volumetric glass wares to room temperature before their use.
9. Chemical compatibility: volumetric glass wares doe not react with the most of the reagents in the clinical laboratory. But compatibility between volumetric glass wares and reagents must be ensured. Use specialised volumetric glass wares for reactive reagents.
Pipettes - various types and different pipetting techniques: Pipettes are used to measure and transfer small volume of liquids. There are various types of pipettes.
1. Micropipettes: They are commonly used in molecular biology, microbiology and analytical chemistry. They are available in several volume ranges such as P2 (0.2 to 2µL), P10 (1 TO 10 µL), P20 (2 to 20 µL), P100 (20 to 100 µL), P200 (20 to 200 µL), P1000 (100 to 1000 µL), etc. They are further divided into single channel and multiple channels.
· Single channel micropipettes: They are used to transfer single volume at one time.
· Multiple channel micropipettes: They have normally 8 or 12channels to pipette. They are used if multiple samples to be pippetted out simultaneously.
2. Pasteur pipette: It is also known as dropper made of glass or plastic. It is not as accurate as micropipette. It is common used to transfer liquid in qualitative analysis.
3. Serological pipette: It is used to delive 1 mL to 50 mL liquid. It is commonly used in cell culture. It is not as accurate as micropipette.
4. Volumetric pipette: It is used to deliver single specific volume with high accuracy. It is commonly used in the analytical chemistry.
Pipetting technique: It is a method to transfer liquid using pipettes.
1. Reverse Pipetting: Suck slight high volume of liquid into pipette than required volume. Touch the pipette tip with side inner wall of the container. Release required volume of liquid into receiving container. It is used for high accuracy.
2. Porward Pipetting: It is standard pipetting technique. Suck required volume of liquid into pipette. Transfer the liquid into receiving container.
3. Multi dispensing: Multi channel pipette is used to transfer multiple samples simultaneously.
4. Air displacement vs positive displacement: Pipettes work on principles air displacement or by creating a vacuum. Micropipettes work on air displacement principle. Plunger is used to create vacuum to suck and transfer liquid. Positive displacement technique is used for viscous or volatile liquid. Here piston directly displaces the liquid.
5. Avoid contamination: Change of pipette tip is required between each transfer to avoid contamination.
6. Calibration: Calibrate the pipette regularly to maintain accuracy..
Biochemical importance of distilled water and deionised water in clinical analysis. Solution and colloids – importance of colloids in biological system. Surface tension, osmosis and viscosity their importance in biological system.
Biochemical importance of distilled water and deionised water in clinical analysis:
Distilled water and deionised water are used in the clinical laboratories due to their unique properties and high purity. Biochemical importance of Distilled water and deionised water is mainly due to their ability to provide a consistent, pure, and contaminant-free medium for preparing reagents, standardizing equipment, diluting samples, and conducting various analytical techniques. Their maintain the accuracy, reliability, and reproducibility of clinical laboratory results. There ultimately contribute to better patient care and scientific research. The followings are the biochemical importance of the in clinical laboratories.
1. Removal of contaminants: Distilled water and deionised water are free from contaminants, ions and impurities. Their high level of purity ensures they do not add unwanted substances that interfere with accuracy of analysis.
2. Reagents preparation: . Various reagents and solutions are used in the clinical laboratories. Distilled water and deionised water Distilled water and deionised water are used in the preparation of these reagents and solutions. Distilled water and deionised water does not add unwanted substances into reagents and solutions during their preparation. This helps to maintain quality of reagents and solutions.
3. Standerdisation of equipments: Many instruments and equipments in the clinical laboratory require Distilled water and deionised water to work effectively. It is mainly due to purity of Distilled water and deionised water. Fir examples Distilled water and deionised water are used to clean, calibrate and standardize pH meter.
4. Sample dilution: Sample are diluted before their analysis. Tap water is not used for dilution due to presence of several minerals and contaminants. These minerals and contaminats interfere in sample analysis. Distilled water and deionised water are free from soluble impurities and contaminants. Thus they are used to dilute samples. This allow accurate analysis of samples.
5. Buffer and media preparations: Buffer and culture media are used in the clinical laboratories. Use of tap water will affect quality of buffer and culture media. This will not give accurate results. Thus, distilled water and deionised water are used in preparation of buffer and culture media to produce reliable and reproducible results.
6. Electrophoresis and chromatography: These methods are most sensitive methods. They require purest form of chemicals. Use of tap water will affect their sensitivity. Thus, Distilled water and deionised water are used for their proper functioning.
Solution and colloids – importance of colloids in biological system. Surface tension, osmosis and viscosity their importance in biological system
Solution: A solution is a homogeneous mixture solute and solvent.. It is composed of on substance dissolved in another substance. Substance that is soluble in other substance is called solute. Substance that dissolves other substance is called solvent. Solution contains solutes as molecules or ions.
Colloid: Colloid is a mixture of tiny particles of one substance evenly dispersed into another substance. These tiny particles are called colloidal particles. Colloidal particles are larger than their molecule size but smaller than particles in suspension. Colloidal particles can be solid liquid or gas. Substance that carries colloidal particles is called continuous medium. Continuous medium may be solid, liquid or gas.
Colloids can scatter light and show Tyndall effect. Tyndall effect is due to size of colloidal particles. Solution does not show Tyndall effect.
Solution is a homogeneous mixture while colloid is heterogeneous mixture. Heterogeneous mixture is an unstable mixture but colloid is a stable mixture.
Importance of colloids in biological system: Colloids have unique properties for various functions in the organism. Colloidal system in the body maintains body fluid balance, blood functions, cellular activities, enzyme reactions, structural support, hormone transport, immune response and several other physiological processes. Biological importance of colloids can be explained as below:
1. Transport of nutrients and waste: Biological fluid such as blood plasma is a colloid. Plasma proteins develop a osmotic pressure that helps to regulate movement of water, nutrients and waste products between blood and surrounding tissues. Osmotic pressure of plasma prevents accumulation of excess fluid in tissue and maintains proper fluid balance.
2. Blood functions: Blood is a colloidal suspension. Red blood cells are suspended in blood plasma. Blood plasma is colloid. RBC transport oxygen and carbon dioxide. Blood colloidal properties develop viscosity in blood. This viscosity is essential for proper blood circulation.
3. Cell Membrane function: Cell membrane is composed of two layers of lipid. These lipid layers have colloidal properties. This colloidal structure control movements of substances into cell and out from the cell.
4. Intracellular Activities: Cells have cytoplasm. Cytoplasm is fluid with colloidal properties.. These colloidal systems help in biochemical reactions and cellular processes.
5. Enzyme function: Enzyme performs its function in colloidal environment. Colloidal environment promote binding of substrate with enzyme.
6. Support and structure: Connective tissues in body have colloidal system. Connective tissues provide structural support to the body.
7. Hormone transport and signalling: Hormones travel inside body through blood and other body fluids. Blood and body fluids are colloidal system.
8. Immune system: Antibodies are protein. They form colloidal complex with antigen.
Surface tension importance in biological system: Surface tension is a physical activity at the surface of a liquid. Surface tension develops at the surface of liquid due to attractive forces between molecules present at the surface of liquid.
Surface tension contributes in biological system such as respiration, digestion, reproduction, cellul;ar functions, protective barriers, capillary actions, etc. The followings are the importance of surface tension in the biological system
1. Respiration: Alveoli are the tiny sacs in the lungs. It has thin layer of water. The surface tension on Alveoli lining prevents collapse of sac during respiration. It helps movement of air and exchange of gases.
2. Capillary action: Blood flows inside blood capillaries against gravitational force. Surface tension develops adhesive force between blood capillary wall and blood. This develops capillary action to flow blood into blood capillaries.
3. Digestion: Liver secretes bile. Bile reduces surface tension of fat drops in the small intestine. This helps to form smaller droplets of fat that helps in digestion of and absorption of fat.
4. Cell membrane formation: Cell membranes are made of double layer of lipids. Surface tension of lipid helps to maintain shape of cells.
5. Protective barriers: Each organ has protective layers of liquid. These protective layers remain on surface of organs due to surface tension. For examples, tears spread over eye surface due to surface tension.
6. Reproduction: Surface tension helps in the movement of sperm in the female reproductive parts.
Osmosis importance in biological system: Movement of solvent molecules through semipermeable membrane from area of lower solute concentration to higher solute concentration is called osmosis.This movement continue till concentration of solute become equal in both side of semipermeable membrane.
Osmosis play important role in biological system. Osmosis maintains cellular structure and function, nutrient absorption, waste elimination, organ functions, cellular signalling and communication, and overall physiological stability in biological system.
Viscosity importance in biological system: Thickness or resistance to flow of fluid is called viscosity. High viscous fluid is thick and resists flowing. Low viscous liquid is thin and easy to flow. Viscosity of body fluids plays important role in biological system.
1. Blood circulation: Viscosity affects blood flow inside blood vessels. High viscosity of blood increases resistance of blood flow. This lead to increase in blood pressure.
2. Oxygen and nutrient delivery: Viscosity of blood affects oxygen and nutrient transportation. High viscous blood slows down delivery of oxygen and nutrients to tissues and organs.
3. Cell movements: Body has various body fluids. Their viscosities affects movement of cells present in body fluids. For example cilia movement in respiratory tract depends upon viscosity of mucus in respiratory tract.
4. Digestive process: Viscosity of food contents in digestive system affects digestion of ffod and their absorption. Appropriate viscosity allows well mixing of enzymes and food.
5. Joint lubrication: Synovial fluids in joint provide lubrication and reduce friction in joints during movement. Appropriate viscosity of synovial fluids requires to avoid damage of bones during movement.
6. Reproductive system: Seminal fluid viscosity affects sperms motility and their movement in female reproductive organs.
Disease and health conditions: Changes in body fluid viscosity develop diseases. Such as increase in number of RBCs increases blood viscosity. It causes blood clotting in blood vesselImportance of Water quality and Glasswares in clinical laboratory: different types of glassware’s, use, cleaning, standardization of volumetric glassware & maintenance. Pipettes - various types and different pipetting techniques.
Importance of Water quality and Glass wares in clinical laboratory:
Importance of Water quality in clinical laboratory: Maintaining water quality in clinical laboratory is essential for accurate and reliable test results, proper functioning of equipments and to ensure best possible patient care. Water quality importance can be explained as per below details:
1. Accuracy of tests: Water is considered as universal solvent. It is used in several laboratory procedures such as reagent preparation, sample dilution, etc. Quality water is free from impurities. It does not interfere in laboratory tests. Quality water such as distilled water leads to accurate diagnosis and tests.
2. Reagent preparation: Reagents require distilled water to ensure effectiveness and quality of reagent. Normal water may contain contaminants that affect the composition of reagents and their effectiveness.
3. Equipment maintenance: High quality water shall be required to clean laboratory equipments. This cleaning prevents contamination. It also ensure accurate result of tests.
4. Reproducibility: Quality water ensure reproducibility of experiments and tests.
Thus, water quality directly affects accuracy of report, reliability of report and validity of diagnostic tests.
Importance of Glass wares in clinical laboratory: Glass wares are transparent, inert, and easy to sterilise. Thus they are ideal to measure liquids, to prepare solution and to conduct experiments. The followings are importance of glass wares in clinical laboratories:
1. Physical properties: Glass wares are transparent and non reactive to most of the reagents and temperature changes. Thus it is most suitable liquids accurately and to perform chemical reactions.
2. Shapes and sizes: Glass wares are available in different shapes and sizes. Thus, they are most suitable for clinical laboratories.
3. Accuracy: Glass wares measure liquid accurately. This ensures reliability of results.
4. Compatibility: Glass wares are inert and resistant to most of the chemicals. It does not contaminate the sample and reagents. It does not interfere during reaction and storage.
5. Transparency: Glass wares are transparent. This reactions, colour changes etc can be observed.
6. Heat resistant: Glass wares tolerate high temperature. Thus it is suitable for sterilisation, evaporation, and boiling of sample or reagent.
7. Ease of cleaning: Glass wares are easy to clean. Thus it does not contaminate the sample or reagent during storage or diagnostic test.
8. Sample storage: Glass wares are non reactive. Thus they are most suitable to store reagents.
9. Longevity: Glass wares have long life span if they are handled carefully.
10. Environmental friendly.
Different types of glassware’s, use: Several types of glass wares are used in clinical laboratories. They are designed for the specific purposes. The followings are the some examples of glass wares and their uses:
1. Beakers: They are cylindrical containers with flat bottom and a spout. Their capacitoes vary from 5 mL to 5000 mL. They are used to mix, to heat and to hold liquids. They are not suitable to measure liquid volume accurately.
2. Flasks: The capacity of flask may vary from 25 mL to 5000 mL. The followings are the types of flasks
· Conical flasks (Erlenmeyer flask): They are cone shaped with narrow neck. They are used to mix, to heat, and to store liquid. Its conical shape allows easy mixing of liquids without splashing.
· Flat bottom round flasks: They are mainly used to heat liquid.
· Round bottom flask: They are mainly used to be heated in a naked flame or in a electrothermal mentle.
· Volumetric flask: They are pear shaped flat bottomed with narrow long neck. Neck has marking that indicates capacity of volumetric flask. Neck is fitted with stopper. They are used to make volume of liquid accurately.
3. Test tubes: They are cylindrical container open at one end. They are used to hold small volume of liquid and to heat them.
4. Watch Glass: They are circular concave shaped piece of glass. They are used to cover beaker mouth. They are also used as surface for evaporation or crystallisation.
5. Petridish: They are circular, shallow dish with lid. They are used to hold culture media, to grow microorganism in culture media and to observe microorganism colony.
6. Funnel: They helps to separate solids from liquid or liquid from liquid or to pour liquid, chemicals and solutions into container.
7. Condenser: They are glass tube with cooling coil. They are used to condense vapour into liquid.
8. Desiccator: They are sealed container with drying agent. They are used to store chemicals sensitive to moisture.
9. Graduate cylinder (Measuring cylinder): They are toll narrow container. They have marking on their wall. They are used to measure volume of liquid. They are not as accurate as pipettes.
10. Burettes: They are long graduated tube with stopcock. They are used to transfer liqids accurately during analysis or titration.
11. Pipettes: They are used to transfer accurate volume of liquid. Pipettes may be micropipettes and volumetric pipettes. Micropipettes are used to transfer liquid in micro litre. Volumetric
12. pipettes are used to transfer liquid in millilitres. There are following five types of pipettes
· Graduated pipettes: They are available from 0.1 to 10 ml capacities.
· Serological pipettes: They are marked upto the tip. They are used to transfer regaents, blood, serum, plasma, etc.
· Mohar pipettes: They are graduated above tip. They are used as serological pipette.
· Volumetric pipettes: They are used to transfer liquid of its full capacity.
· Pasteur pipettes: They are used to separate plasma and serum from cells.
Cleaning of glass wares: Cleaning of glass wares is essential step for reliable laboratory test report. The following guide lines are followed to clean glass wares.
1. Pre rinsing: Rinse the glass ware immediately after use. Rinse the glass wares suitable liquids that can dissolve the contents of container. For example water, acetone etc.
2. Soaking: Soaking is used to remove stubborn residues on glass container wall. Cleaning solution such as mild detergent solutions, enzymatic cleaners, acid base solution are used in soaking step.
3. Brushing: Soft brush or scrub is used to remove contents from outer and inner wall of the container soaked in soaking solution.
4. Rinsing: Rinse the glass ware thoroughly with purified water. This remave the trace of cleaning agents present on the wall of containers. Repeat the rinsing multiple times.
5. Drying: Allow the glass ware to dry in air after rinsing. Sometimes oven at low temperature is used to dry glass wares.
Precautions: Avoid use of hard scrub or brush, acid cleaning agent, and scratching on glass ware wall.
Standardization of volumetric glassware: Standerdisation of volumetric glasswares is done to ensure accuracy of glasswares. Volumetric glassware, such as volumetric flasks, pipettes, and burettes, are used to measure volumes of liquids in laboratory.
Volumetric glasswares are staderdised as per below
1. Volumetric flask: Volumetric flask is used to prepare solutions with accuracy. Volumetric flask is standerdised by using solution of known concentration. Solution is added upto calibration mark on the neck of volumetric flask. Mass of solution and density of solution are used to calculate volume of solution in the volumetric flask.
2. Ppette: Pipette is used to transfer accurate volume of liquid. Solution of known concentration is drawn into pipette. Solution is transferred into a container. It volume or mass is measured. Difference between initial mass and final mass or volume gives accuracy of the pipette.
3. Pipette: Burette is used to deliver known volume of liquid during titration. Solution of known concentration is added into burette. Initial volume of liquid in burette is noted. Solution is allowed to drain out from burette into container until endpoint of titration. Difference between initial volume and final volume in burette indicates volume of liquid delivered by the burette.
Maintenance of volumetric glassware: Maintenance of volumetric glass wares in the clinical laboratory ensures accuracy and reliability of measurements of chemicals and reagents. The volumetric glass wares are maintained in the clinical laboratory as per below
1. Cleaning: Regular cleaning of glass wares prevents contamination and ensure accurate measurement. Mild detergent or specialised glassware cleaner with deionised water are used to clean glass wares. After cleaning rinse the glass wares using deionised water to remove any residue.
2. Drying: Allow glass wares to dry in air or in oven at low temperature. Avoid cloth or paper or towel to dry interior part of glass wares.
3. Calibration: Volumetric glass wares of calibration marks. It indicates volume of contents in the volumetric glass wares. Check this mark regularly using reference standards. If require, recalibrate.
4. Record keeping: Maintain proper record of date of calibration. This helps to know the reliability of volumetric glass wares.
5. Regular inspection: Regularly inspect the volumetric glass wares for damage such as cracks, scratches, etc.
6. Storage: Store volumetric glass wares in a clean and dust free area. Use protective caps to prevent entry of dust or contamination into volumetric glass wares.
7. Handling: Handle volumetric glass wares with great care and caution. Hold it by the appropriate part of volumetric glass wares such as neck of the flask.
8. Temperature: volumetric glass wares expand or contract with temperature changes. Allow volumetric glass wares to room temperature before their use.
9. Chemical compatibility: volumetric glass wares doe not react with the most of the reagents in the clinical laboratory. But compatibility between volumetric glass wares and reagents must be ensured. Use specialised volumetric glass wares for reactive reagents.
Pipettes - various types and different pipetting techniques: Pipettes are used to measure and transfer small volume of liquids. There are various types of pipettes.
1. Micropipettes: They are commonly used in molecular biology, microbiology and analytical chemistry. They are available in several volume ranges such as P2 (0.2 to 2µL), P10 (1 TO 10 µL), P20 (2 to 20 µL), P100 (20 to 100 µL), P200 (20 to 200 µL), P1000 (100 to 1000 µL), etc. They are further divided into single channel and multiple channels.
· Single channel micropipettes: They are used to transfer single volume at one time.
· Multiple channel micropipettes: They have normally 8 or 12channels to pipette. They are used if multiple samples to be pippetted out simultaneously.
2. Pasteur pipette: It is also known as dropper made of glass or plastic. It is not as accurate as micropipette. It is common used to transfer liquid in qualitative analysis.
3. Serological pipette: It is used to delive 1 mL to 50 mL liquid. It is commonly used in cell culture. It is not as accurate as micropipette.
4. Volumetric pipette: It is used to deliver single specific volume with high accuracy. It is commonly used in the analytical chemistry.
Pipetting technique: It is a method to transfer liquid using pipettes.
1. Reverse Pipetting: Suck slight high volume of liquid into pipette than required volume. Touch the pipette tip with side inner wall of the container. Release required volume of liquid into receiving container. It is used for high accuracy.
2. Porward Pipetting: It is standard pipetting technique. Suck required volume of liquid into pipette. Transfer the liquid into receiving container.
3. Multi dispensing: Multi channel pipette is used to transfer multiple samples simultaneously.
4. Air displacement vs positive displacement: Pipettes work on principles air displacement or by creating a vacuum. Micropipettes work on air displacement principle. Plunger is used to create vacuum to suck and transfer liquid. Positive displacement technique is used for viscous or volatile liquid. Here piston directly displaces the liquid.
5. Avoid contamination: Change of pipette tip is required between each transfer to avoid contamination.
6. Calibration: Calibrate the pipette regularly to maintain accuracy..
Biochemical importance of distilled water and deionised water in clinical analysis. Solution and colloids – importance of colloids in biological system. Surface tension, osmosis and viscosity their importance in biological system.
Biochemical importance of distilled water and deionised water in clinical analysis:
Distilled water and deionised water are used in the clinical laboratories due to their unique properties and high purity. Biochemical importance of Distilled water and deionised water is mainly due to their ability to provide a consistent, pure, and contaminant-free medium for preparing reagents, standardizing equipment, diluting samples, and conducting various analytical techniques. Their maintain the accuracy, reliability, and reproducibility of clinical laboratory results. There ultimately contribute to better patient care and scientific research. The followings are the biochemical importance of the in clinical laboratories.
1. Removal of contaminants: Distilled water and deionised water are free from contaminants, ions and impurities. Their high level of purity ensures they do not add unwanted substances that interfere with accuracy of analysis.
2. Reagents preparation: . Various reagents and solutions are used in the clinical laboratories. Distilled water and deionised water Distilled water and deionised water are used in the preparation of these reagents and solutions. Distilled water and deionised water does not add unwanted substances into reagents and solutions during their preparation. This helps to maintain quality of reagents and solutions.
3. Standerdisation of equipments: Many instruments and equipments in the clinical laboratory require Distilled water and deionised water to work effectively. It is mainly due to purity of Distilled water and deionised water. Fir examples Distilled water and deionised water are used to clean, calibrate and standardize pH meter.
4. Sample dilution: Sample are diluted before their analysis. Tap water is not used for dilution due to presence of several minerals and contaminants. These minerals and contaminats interfere in sample analysis. Distilled water and deionised water are free from soluble impurities and contaminants. Thus they are used to dilute samples. This allow accurate analysis of samples.
5. Buffer and media preparations: Buffer and culture media are used in the clinical laboratories. Use of tap water will affect quality of buffer and culture media. This will not give accurate results. Thus, distilled water and deionised water are used in preparation of buffer and culture media to produce reliable and reproducible results.
6. Electrophoresis and chromatography: These methods are most sensitive methods. They require purest form of chemicals. Use of tap water will affect their sensitivity. Thus, Distilled water and deionised water are used for their proper functioning.
Solution and colloids – importance of colloids in biological system. Surface tension, osmosis and viscosity their importance in biological system
Solution: A solution is a homogeneous mixture solute and solvent.. It is composed of on substance dissolved in another substance. Substance that is soluble in other substance is called solute. Substance that dissolves other substance is called solvent. Solution contains solutes as molecules or ions.
Colloid: Colloid is a mixture of tiny particles of one substance evenly dispersed into another substance. These tiny particles are called colloidal particles. Colloidal particles are larger than their molecule size but smaller than particles in suspension. Colloidal particles can be solid liquid or gas. Substance that carries colloidal particles is called continuous medium. Continuous medium may be solid, liquid or gas.
Colloids can scatter light and show Tyndall effect. Tyndall effect is due to size of colloidal particles. Solution does not show Tyndall effect.
Solution is a homogeneous mixture while colloid is heterogeneous mixture. Heterogeneous mixture is an unstable mixture but colloid is a stable mixture.
Importance of colloids in biological system: Colloids have unique properties for various functions in the organism. Colloidal system in the body maintains body fluid balance, blood functions, cellular activities, enzyme reactions, structural support, hormone transport, immune response and several other physiological processes. Biological importance of colloids can be explained as below:
1. Transport of nutrients and waste: Biological fluid such as blood plasma is a colloid. Plasma proteins develop a osmotic pressure that helps to regulate movement of water, nutrients and waste products between blood and surrounding tissues. Osmotic pressure of plasma prevents accumulation of excess fluid in tissue and maintains proper fluid balance.
2. Blood functions: Blood is a colloidal suspension. Red blood cells are suspended in blood plasma. Blood plasma is colloid. RBC transport oxygen and carbon dioxide. Blood colloidal properties develop viscosity in blood. This viscosity is essential for proper blood circulation.
3. Cell Membrane function: Cell membrane is composed of two layers of lipid. These lipid layers have colloidal properties. This colloidal structure control movements of substances into cell and out from the cell.
4. Intracellular Activities: Cells have cytoplasm. Cytoplasm is fluid with colloidal properties.. These colloidal systems help in biochemical reactions and cellular processes.
5. Enzyme function: Enzyme performs its function in colloidal environment. Colloidal environment promote binding of substrate with enzyme.
6. Support and structure: Connective tissues in body have colloidal system. Connective tissues provide structural support to the body.
7. Hormone transport and signalling: Hormones travel inside body through blood and other body fluids. Blood and body fluids are colloidal system.
8. Immune system: Antibodies are protein. They form colloidal complex with antigen.
Surface tension importance in biological system: Surface tension is a physical activity at the surface of a liquid. Surface tension develops at the surface of liquid due to attractive forces between molecules present at the surface of liquid.
Surface tension contributes in biological system such as respiration, digestion, reproduction, cellul;ar functions, protective barriers, capillary actions, etc. The followings are the importance of surface tension in the biological system
1. Respiration: Alveoli are the tiny sacs in the lungs. It has thin layer of water. The surface tension on Alveoli lining prevents collapse of sac during respiration. It helps movement of air and exchange of gases.
2. Capillary action: Blood flows inside blood capillaries against gravitational force. Surface tension develops adhesive force between blood capillary wall and blood. This develops capillary action to flow blood into blood capillaries.
3. Digestion: Liver secretes bile. Bile reduces surface tension of fat drops in the small intestine. This helps to form smaller droplets of fat that helps in digestion of and absorption of fat.
4. Cell membrane formation: Cell membranes are made of double layer of lipids. Surface tension of lipid helps to maintain shape of cells.
5. Protective barriers: Each organ has protective layers of liquid. These protective layers remain on surface of organs due to surface tension. For examples, tears spread over eye surface due to surface tension.
6. Reproduction: Surface tension helps in the movement of sperm in the female reproductive parts.
Osmosis importance in biological system: Movement of solvent molecules through semipermeable membrane from area of lower solute concentration to higher solute concentration is called osmosis. This movement continue till concentration of solute become equal in both side of semipermeable membrane.
Osmosis play important role in biological system. Osmosis maintains cellular structure and function, nutrient absorption, waste elimination, organ functions, cellular signalling and communication, and overall physiological stability in biological system.
Viscosity importance in biological system: Thickness or resistance to flow of fluid is called viscosity. High viscous fluid is thick and resists flowing. Low viscous liquid is thin and easy to flow. Viscosity of body fluids plays important role in biological system.
1. Blood circulation: Viscosity affects blood flow inside blood vessels. High viscosity of blood increases resistance of blood flow. This lead to increase in blood pressure.
2. Oxygen and nutrient delivery: Viscosity of blood affects oxygen and nutrient transportation. High viscous blood slows down delivery of oxygen and nutrients to tissues and organs.
3. Cell movements: Body has various body fluids. Their viscosities affects movement of cells present in body fluids. For example cilia movement in respiratory tract depends upon viscosity of mucus in respiratory tract.
4. Digestive process: Viscosity of food contents in the digestive system affects digestion of food and their absorption. Appropriate viscosity allows well mixing of enzymes and food.
5. Joint lubrication: Synovial fluids in joints provide lubrication and reduce friction in joints during movement. Appropriate viscosity of synovial fluids requires to avoid damage of bones during movement.
6. Reproductive system: Seminal fluid viscosity affects sperms motility and their movement in female reproductive organs.
Disease and health conditions: Changes in body fluid viscosity develop diseases. Such as increase in number of RBCs increases blood viscosity. It causes blood clotting in blood vessel
Author: Dr Pramila Singh