Laboratory instruments and equipments

Mr. Arvind Kumar

Introduction

  • Medical laboratory instruments and equipment play a vital role in the accurate diagnosis, monitoring, and treatment of diseases.

  • These tools, ranging from simple microscopes and centrifuges to advanced analyzers and incubators, ensure precision in laboratory investigations.

  • The reliability of laboratory results depends not only on the proper use of these instruments but also on their regular care and maintenance.

  • Proper handling, routine cleaning, timely calibration, and adherence to safety protocols help extend the lifespan of equipment, minimize errors, and ensure consistent performance.

  • A well-maintained laboratory environment not only supports efficiency but also safeguards the health of laboratory personnel and patients by reducing the risk of contamination and inaccurate results.

 

Analytical & Diagnostic Instruments

Spectrophotometer

Working Principle:

  1. A spectrophotometer works on the principle of Beer-Lambert’s Law, which states that the absorbance of light by a solution is directly proportional to the concentration of the solute and the path length of the light through the solution.

  2. A light source emits a broad spectrum of light, which passes through a monochromator (prism or diffraction grating) to isolate a specific wavelength.

  3. The selected wavelength of light is directed through the sample solution placed in a cuvette.

  4. The amount of light absorbed by the solution is measured by a photodetector, which converts the transmitted light into an electrical signal.

  5. The spectrophotometer then displays absorbance or transmittance values, which can be used to determine the concentration of the analyte.

Uses:

  1. Quantitative estimation of biomolecules such as proteins, nucleic acids, and enzymes.

  2. Measurement of blood and urine analytes in clinical laboratories.

  3. Determination of drug concentration in pharmaceutical analysis.

  4. Study of enzyme kinetics and reaction rates.

  5. Identification of compounds based on their absorption spectra.

  6. Quality control in food, chemical, and biochemical industries.

  7. Measurement of bacterial growth by optical density at 600 nm (OD600).

  8. Environmental monitoring, such as analysis of pollutants in water.

Care:

  1. Handle the instrument gently and place it on a stable, vibration-free surface.

  2. Always use clean and scratch-free cuvettes to avoid light scattering and errors.

  3. Do not touch cuvette surfaces with bare fingers; use lint-free tissue.

  4. Ensure that the light source (lamp) is not switched on unnecessarily to increase its lifespan.

  5. Keep the sample chamber free from dust, spills, and moisture.

  6. Cover the spectrophotometer when not in use to protect it from dust.

Maintenance:

  1. Perform regular calibration using standard solutions or reference filters to maintain accuracy.

  2. Periodically check and replace the light source (tungsten or deuterium lamp) when intensity decreases.

  3. Inspect and clean the monochromator and optical path with appropriate cleaning agents if required.

  4. Verify wavelength accuracy with calibration standards at set intervals.

  5. Maintain the photodetector by ensuring it is free of dust and functioning properly.

  6. Follow the manufacturer’s recommended service schedule for preventive maintenance.

  7. Keep proper records of calibration, servicing, and repairs for quality assurance.

  8. Ensure proper electrical supply with a stabilizer or UPS to prevent voltage fluctuations.

Colorimeter

Working Principle:

  1. A colorimeter works on the principle of Beer-Lambert’s Law, where the intensity of color of a solution is proportional to the concentration of the colored solute.

  2. A specific wavelength of light is passed through a solution in a cuvette.

  3. The solution absorbs some of the light, and the remaining transmitted light reaches the detector.

  4. The detector converts light intensity into an electrical signal.

  5. The instrument calculates either absorbance or transmittance, which can be correlated with the solute concentration.

  6. Only solutions that are colored or can form a colored complex can be analyzed.

Uses:

  1. Quantitative determination of colored compounds in clinical samples (e.g., hemoglobin, bilirubin).

  2. Estimation of enzyme activity in biochemical studies.

  3. Measurement of concentration in pharmaceutical formulations.

  4. Determination of protein concentration using colorimetric assays (e.g., Biuret, Lowry).

  5. Environmental monitoring such as water analysis for pollutants or chemical contaminants.

  6. Food industry applications for color intensity analysis.

  7. Quality control and standardization in chemical and biochemical laboratories.

Care:

  1. Use clean and scratch-free cuvettes to avoid errors.

  2. Do not touch cuvette surfaces with bare fingers; use lint-free tissue or gloves.

  3. Handle the instrument gently and place it on a stable, vibration-free surface.

  4. Keep the instrument covered when not in use to prevent dust accumulation.

  5. Avoid spilling liquids on the instrument, especially near the optical path and detector.

  6. Ensure proper alignment of the cuvette in the sample holder for accurate readings.

Maintenance:

  1. Regularly calibrate the colorimeter using standard solutions or reference filters.

  2. Inspect the light source (usually tungsten or LED) and replace it if intensity decreases.

  3. Clean the optical path and lenses carefully as per manufacturer guidelines.

  4. Verify wavelength accuracy periodically to maintain precision.

  5. Keep proper documentation of calibration, servicing, and any repairs.

  6. Ensure stable electrical supply; use a voltage stabilizer or UPS if necessary.

  7. Follow manufacturer’s preventive maintenance schedule to avoid sudden breakdowns.

  8. Store the instrument in a clean, dry place and avoid exposure to high temperature or humidity.

pH Meter

Working Principle:

  1. A pH meter measures the hydrogen ion concentration (pH) of a solution using an electrochemical method.

  2. It consists of a glass electrode (measuring electrode) and a reference electrode connected to a voltmeter or a digital display.

  3. The glass electrode develops a potential (voltage) proportional to the hydrogen ion activity in the solution.

  4. The reference electrode provides a stable reference potential.

  5. The pH meter measures the potential difference between the electrodes and converts it into a pH value using calibration curves.

  6. It works accurately only when properly calibrated with standard buffer solutions.

Uses:

  1. Measurement of pH in biological samples like blood, urine, and serum.

  2. Determination of pH in pharmaceutical formulations.

  3. Monitoring pH in chemical and biochemical reactions.

  4. Measurement of pH in water, soil, and environmental samples.

  5. Industrial applications in food, beverage, and chemical industries.

  6. Quality control in laboratories to maintain optimal conditions for experiments.

Care:

  1. Always rinse the electrode with distilled water before and after use.

  2. Avoid touching the glass electrode surface with fingers.

  3. Do not allow the electrode to dry out; store it in electrode storage solution.

  4. Handle the instrument gently and avoid sudden shocks or vibrations.

  5. Avoid contamination of the electrode by immersing it only in the sample solution.

  6. Keep the meter and electrodes clean and dust-free.

Maintenance:

  1. Calibrate the pH meter regularly using standard buffer solutions (pH 4, 7, 10).

  2. Replace the electrode if response becomes slow or inaccurate.

  3. Store the electrode in storage solution or a moist environment to prevent drying.

  4. Check the reference electrode solution periodically and refill if necessary.

  5. Inspect cables and connections for damage; replace if needed.

  6. Follow the manufacturer’s preventive maintenance schedule.

  7. Keep proper records of calibration, maintenance, and electrode replacement.

  8. Ensure stable power supply and avoid voltage fluctuations to protect the instrument.

Electrophoresis

Working Principle:

  1. Electrophoresis is a technique used to separate charged molecules (like proteins, nucleic acids) based on their size and charge.

  2. It works on the principle that charged particles move in an electric field: cations move toward the cathode and anions toward the anode.

  3. Molecules are applied to a support medium such as agarose gel, polyacrylamide gel, or cellulose acetate.

  4. When an electric current is applied, molecules migrate through the medium at rates proportional to their size, shape, and charge.

  5. After separation, molecules are visualized using dyes or staining methods (e.g., Coomassie Blue for proteins, ethidium bromide for DNA).

Uses:

  1. Separation and analysis of proteins in clinical and research laboratories.

  2. DNA and RNA analysis in molecular biology studies.

  3. Detection of genetic disorders or mutations.

  4. Purification of biomolecules for further biochemical experiments.

  5. Identification of microorganisms in microbiology using protein or DNA profiles.

  6. Quality control in biotechnology and pharmaceutical industries.

  7. Forensic applications for DNA fingerprinting and paternity testing.

  8. Measurement of enzyme isoforms or hemoglobin variants.

Care:

  1. Handle gels carefully to prevent tearing or damage.

  2. Use clean and dry electrodes and buffer chambers.

  3. Avoid spilling buffer or samples on the power supply or unit.

  4. Do not overload wells with sample to ensure proper separation.

  5. Keep the electrophoresis chamber and accessories covered when not in use to prevent dust accumulation.

  6. Follow proper electrical safety precautions while using the apparatus.

Maintenance:

  1. Regularly clean the gel trays, combs, and buffer chambers after use.

  2. Inspect electrodes and wiring for corrosion or damage.

  3. Ensure proper functioning of the power supply before each experiment.

  4. Replace worn-out or damaged components like electrodes, combs, or gel trays.

  5. Store the electrophoresis unit in a dry and dust-free environment.

  6. Keep records of maintenance, repairs, and calibrations.

  7. Avoid long-term storage of gels in the chamber to prevent damage to the unit.

  8. Follow manufacturer guidelines for periodic preventive maintenance of the instrument.

Centrifuge

Working Principle:

  1. A centrifuge works on the principle of centrifugal force, which separates components of a mixture based on their density.

  2. When a sample is rotated at high speeds, denser particles move outward toward the bottom of the tube, while lighter components remain closer to the top.

  3. The relative centrifugal force (RCF) depends on the speed (rpm) and radius of rotation.

  4. Different types of centrifuges (e.g., microcentrifuge, high-speed, ultracentrifuge) are used depending on the sample type and separation requirement.

  5. Separation can be for solids from liquids, different cellular components, or macromolecules like proteins and nucleic acids.

Uses:

  1. Separation of blood components such as plasma, serum, and blood cells.

  2. Isolation of cellular organelles like nuclei, mitochondria, and lysosomes.

  3. Purification of proteins, DNA, and RNA in biochemical experiments.

  4. Removal of debris from samples before analysis.

  5. Concentration of microorganisms or particulate matter.

  6. Clinical laboratories for urine, CSF, and other body fluid analyses.

  7. Industrial applications for separating emulsions or suspensions.

  8. Preparation of samples for electrophoresis or other analytical procedures.

Care:

  1. Ensure tubes are properly balanced before starting the centrifuge to avoid vibrations and damage.

  2. Use compatible centrifuge tubes and do not exceed the recommended volume.

  3. Close the lid properly before switching on the instrument.

  4. Handle the rotor carefully; avoid touching it with bare hands to prevent corrosion.

  5. Keep the centrifuge clean and free from spills, dust, and debris.

  6. Avoid sudden stops or changes in speed that may damage the rotor or samples.

Maintenance:

  1. Regularly inspect the rotor for signs of corrosion, cracks, or wear.

  2. Lubricate moving parts as per manufacturer guidelines to ensure smooth operation.

  3. Periodically calibrate the speed and temperature (for refrigerated centrifuges).

  4. Clean the chamber and rotor with mild detergents and distilled water; avoid harsh chemicals.

  5. Replace worn-out or damaged rotor, lid, or seals immediately.

  6. Keep records of service, calibration, and preventive maintenance.

  7. Ensure proper electrical supply with voltage stabilizers to protect the motor and electronics.

  8. Follow the manufacturer-recommended preventive maintenance schedule to prolong instrument life.

Flame Photometer

Working Principle:

  1. A flame photometer works on the principle of emission spectrophotometry, where atoms of certain elements emit light when heated in a flame.

  2. The sample solution is aspirated into a flame, usually fueled by air and acetylene.

  3. The heat of the flame excites the metal ions (e.g., Na⁺, K⁺, Ca²⁺, Li⁺) in the solution, causing them to emit light at characteristic wavelengths.

  4. A filter or monochromator isolates the specific wavelength of emitted light.

  5. The intensity of the emitted light is measured by a photodetector and is directly proportional to the concentration of the element in the sample.

Uses:

  1. Quantitative estimation of sodium (Na⁺), potassium (K⁺), lithium (Li⁺), and calcium (Ca²⁺) in biological fluids.

  2. Monitoring electrolyte balance in clinical samples like blood serum, plasma, and urine.

  3. Determination of trace elements in pharmaceutical and industrial samples.

  4. Soil and water analysis for metal ions in environmental studies.

  5. Quality control in food and beverage industries for mineral content.

  6. Biochemical studies requiring measurement of ionic concentrations.

Care:

  1. Use clean and dry sample containers and aspirators to avoid contamination.

  2. Handle the instrument gently and avoid spilling samples on the flame or detector.

  3. Ensure the flame is stable and the fuel supply (acetylene) is secure.

  4. Avoid touching the optical parts with bare hands; use lint-free tissue if cleaning is needed.

  5. Keep the instrument covered when not in use to prevent dust accumulation.

Maintenance:

  1. Regularly clean the nebulizer, burner, and aspirator to prevent blockages.

  2. Inspect and replace worn or damaged parts like the fuel hose or burner tip.

  3. Calibrate the instrument periodically using standard solutions of known concentration.

  4. Ensure proper alignment of filters or monochromators for accurate measurements.

  5. Keep proper records of maintenance, calibration, and repairs.

  6. Follow manufacturer guidelines for preventive maintenance and service schedule.

  7. Ensure a stable electrical supply and proper ventilation to prevent overheating.

  8. Check flame color and stability before every use to ensure accurate readings.

Blood Gas Analyzer

Working Principle:

  1. A blood gas analyzer measures partial pressures of gases (pO₂, pCO₂), pH, and electrolytes in blood using electrochemical sensors.

  2. The Clark electrode is used to measure oxygen (pO₂) based on current generated by oxygen reduction at the cathode.

  3. The Severinghaus electrode measures carbon dioxide (pCO₂) via a pH change in a bicarbonate solution equilibrated with CO₂.

  4. The glass electrode is used to determine hydrogen ion concentration (pH).

  5. Some modern analyzers also use ion-selective electrodes to measure electrolytes such as Na⁺, K⁺, and Ca²⁺.

  6. The instrument converts the electrical signals from the electrodes into digital readings, providing accurate values of blood gases, pH, and electrolytes.

Uses:

  1. Assessment of acid-base balance in patients.

  2. Measurement of oxygenation and ventilation status in critically ill patients.

  3. Monitoring respiratory and metabolic disorders.

  4. Guiding therapy in intensive care, anesthesia, and emergency medicine.

  5. Measurement of electrolytes in blood for clinical management.

  6. Evaluation of patients with cardiac or pulmonary diseases.

  7. Monitoring patients on mechanical ventilation.

Care:

  1. Handle blood samples carefully to avoid air bubbles or clotting.

  2. Use clean syringes and capillary tubes for sampling.

  3. Ensure electrodes are clean and free from contamination.

  4. Avoid touching sensitive electrodes with bare hands.

  5. Keep the analyzer in a clean, dust-free, and vibration-free environment.

  6. Follow proper sample handling and storage guidelines to maintain accuracy.

Maintenance:

  1. Calibrate the electrodes regularly using standard calibration solutions.

  2. Replace electrodes or membranes as per manufacturer guidelines.

  3. Perform periodic quality control tests using control solutions.

  4. Clean the sample chamber, electrodes, and other components as recommended.

  5. Keep logs of calibration, maintenance, and quality control for records.

  6. Ensure stable power supply and check electrical connections regularly.

  7. Follow manufacturer’s preventive maintenance schedule to ensure long-term reliability.

  8. Check and refill reference solutions and buffers when required.

 

Sample Handling & Preparation

Vortex Mixer

Working Principle:

  1. A vortex mixer works on the principle of circular motion to mix small volumes of liquid rapidly.

  2. The motorized platform or cup holder oscillates in a circular or orbital motion.

  3. When a test tube or container is pressed against the platform, the liquid inside is subjected to rapid swirling, creating a vortex.

  4. The vortex motion mixes the contents uniformly in a short period.

  5. The speed of the vortex can often be adjusted depending on the mixing requirement.

Uses:

  1. Mixing reagents in test tubes, microcentrifuge tubes, or small containers.

  2. Dissolving solids in liquids or resuspending precipitates.

  3. Preparation of chemical, biochemical, or microbiological samples.

  4. Homogenization of samples before analysis.

  5. Rapid mixing in ELISA or other enzyme assays.

  6. Mixing of DNA, RNA, or protein solutions in molecular biology experiments.

Care:

  1. Place the mixer on a stable, vibration-free surface to prevent movement.

  2. Avoid overloading the platform with heavy tubes or containers.

  3. Ensure the tubes are properly closed to prevent spillage.

  4. Keep the device clean and free from dust and liquid spills.

  5. Do not press the tube too hard against the platform to avoid damage.

  6. Use tubes compatible with the mixer to avoid imbalance.

Maintenance:

  1. Regularly inspect the power cord and plug for damage.

  2. Lubricate moving parts if recommended by the manufacturer.

  3. Check and tighten screws or fasteners periodically.

  4. Clean the platform with a mild detergent and soft cloth.

  5. Avoid exposure to excessive moisture or corrosive chemicals.

  6. Follow manufacturer’s preventive maintenance schedule for the motor.

  7. Keep records of service or repairs if any.

  8. Ensure proper electrical supply and avoid voltage fluctuations to prevent motor damage.

Water Bath

Working Principle:

  1. A water bath works on the principle of heat transfer through water to maintain a uniform temperature for samples.

  2. It consists of a container filled with water and an electric heating element to heat the water.

  3. A thermostat or digital controller regulates the temperature by switching the heater on and off.

  4. The heated water provides indirect, uniform heating to the sample containers placed in it.

  5. Some water baths also include circulating pumps to ensure even temperature distribution.

Uses:

  1. Incubation of biological samples at a constant temperature.

  2. Warming reagents before experiments.

  3. Enzyme reactions and biochemical assays requiring controlled temperature.

  4. Thawing frozen samples or melting agar/media.

  5. Sterilization or heating of certain laboratory glassware and containers.

  6. Maintenance of cell cultures or bacterial cultures at optimal temperatures.

  7. Heat inactivation of serum or other biological samples.

Care:

  1. Always use distilled water to prevent mineral buildup.

  2. Ensure water level is sufficient to cover the sample containers properly.

  3. Avoid direct contact of electrical parts with water.

  4. Keep the bath clean and free from spills or debris.

  5. Monitor the temperature to prevent overheating.

  6. Do not allow water to boil dry during use.

Maintenance:

  1. Regularly clean the bath using mild detergent and rinse thoroughly.

  2. Change water frequently to prevent bacterial growth and mineral deposits.

  3. Inspect heating elements for signs of wear or corrosion.

  4. Calibrate the temperature controller periodically for accuracy.

  5. Check and maintain the thermostat or digital control system.

  6. Keep a log of maintenance, cleaning, and calibration.

  7. Store the bath in a dry, dust-free environment when not in use.

  8. Follow manufacturer’s preventive maintenance instructions to ensure long-term reliability.

Hot Plate

Working Principle:

  1. A hot plate works on the principle of electrical resistance heating, where electric current passes through a heating element to generate heat.

  2. The heat is transferred to the plate surface and subsequently to the container placed on it.

  3. Some hot plates include a magnetic stirrer, which allows simultaneous heating and mixing of liquids.

  4. Temperature is controlled using a thermostat or digital controller to maintain the desired heat level.

  5. Heat transfer is mostly direct, requiring careful monitoring of temperature-sensitive samples.

Uses:

  1. Heating of chemicals and solutions in laboratories.

  2. Melting of solids or reagents.

  3. Boiling of water or other liquids for experiments.

  4. Preparation of culture media or agar plates.

  5. Evaporation of solvents in sample preparation.

  6. Heating samples before chemical reactions.

  7. Combined heating and stirring in biochemical and molecular biology experiments (for magnetic stirrer hot plates).

Care:

  1. Ensure the hot plate is placed on a stable, heat-resistant surface.

  2. Avoid spilling liquids on the plate or electrical parts.

  3. Do not touch the surface while it is hot; use heat-resistant gloves.

  4. Keep the surface clean and free from chemical residues.

  5. Avoid overheating or running the hot plate empty for long periods.

  6. Use appropriate containers compatible with the hot plate surface.

Maintenance:

  1. Regularly inspect the power cord, plug, and control knobs for damage.

  2. Clean the surface with a damp cloth and mild detergent; avoid abrasive cleaners.

  3. Check temperature accuracy with a thermometer periodically.

  4. Ensure that magnetic stirrer functionality is working properly (if applicable).

  5. Replace worn-out or damaged heating elements as recommended by the manufacturer.

  6. Follow the manufacturer’s preventive maintenance schedule for long-term reliability.

  7. Keep records of service, repairs, and calibration for quality assurance.

  8. Ensure stable electrical supply and avoid voltage fluctuations to prevent damage.

Incubator

Working Principle:

  1. An incubator works on the principle of maintaining a controlled environment for the growth of microorganisms, cells, or tissues.

  2. It provides constant temperature, usually through an electric heating element regulated by a thermostat or digital controller.

  3. Humidity can be maintained using a water reservoir in the incubator chamber.

  4. Some incubators also provide CO₂ control for cell culture experiments, maintaining pH and optimal growth conditions.

  5. Air circulation is often ensured with fans to maintain uniform temperature and gas distribution throughout the chamber.

Uses:

  1. Growth and maintenance of bacterial, fungal, or other microbial cultures.

  2. Incubation of cell cultures for research or clinical studies.

  3. Culture of embryos or other biological samples in research labs.

  4. Biochemical and molecular biology experiments requiring constant temperature.

  5. Study of microbial growth kinetics and antibiotic susceptibility.

  6. Maintenance of clinical specimens before analysis.

  7. Environmental testing of samples at controlled temperature.

Care:

  1. Keep the incubator clean and free from dust.

  2. Avoid overloading the shelves with samples to allow proper air circulation.

  3. Monitor water reservoir (if humidity is required) to prevent drying out.

  4. Avoid spilling liquids on electrical components.

  5. Keep the door closed as much as possible to maintain temperature stability.

  6. Handle samples carefully to prevent contamination.

Maintenance:

  1. Regularly clean and disinfect the chamber, shelves, and water reservoir.

  2. Calibrate the temperature and CO₂ (if applicable) periodically for accuracy.

  3. Inspect and service electrical components, heating elements, and fans.

  4. Replace worn-out seals or door gaskets to maintain airtight conditions.

  5. Keep a log of calibration, maintenance, and repairs.

  6. Check and refill humidity or CO₂ systems as needed.

  7. Ensure a stable electrical supply to avoid fluctuations that can damage the incubator.

  8. Follow the manufacturer’s preventive maintenance schedule to prolong equipment life.

 

Imaging Equipment

Compound Microscope

Working Principle:

  1. A compound microscope works on the principle of light refraction to magnify small objects.

  2. It uses two sets of lenses: the objective lens (close to the specimen) and the ocular lens (eyepiece) to achieve high magnification.

  3. Light from an illuminator or mirror passes through the specimen, is refracted by the objective lens to form a real image, and then magnified by the ocular lens to form a virtual image.

  4. Total magnification is calculated as the product of the objective lens magnification and the ocular lens magnification.

  5. Fine and coarse focus adjustments allow clear visualization of specimens at different magnifications.

Uses:

  1. Observation and study of cells, tissues, and microorganisms in biological and clinical laboratories.

  2. Examination of blood smears, urine sediments, and microbial cultures.

  3. Study of plant and animal histology for research or teaching purposes.

  4. Microbiological analysis of bacteria, fungi, and protozoa.

  5. Quality control in pharmaceutical and food industries.

  6. Research in molecular biology, pathology, and biochemistry.

  7. Identification of structural abnormalities in clinical specimens.

Care:

  1. Handle the microscope carefully and avoid sudden movements or shocks.

  2. Keep lenses clean using lens paper; avoid touching them with fingers.

  3. Always cover the microscope with a dust cover when not in use.

  4. Avoid exposure to direct sunlight or high humidity.

  5. Do not use excessive force on focus knobs or stage adjustments.

  6. Clean the stage and body with a soft, dry cloth regularly.

Maintenance:

  1. Regularly clean and inspect objective and ocular lenses; replace if damaged.

  2. Check the light source or mirror for proper illumination.

  3. Ensure smooth functioning of mechanical parts like stage, focus knobs, and condenser.

  4. Lubricate moving parts if recommended by the manufacturer.

  5. Keep a record of servicing, calibration, and repairs.

  6. Store the microscope in a dry, dust-free, and stable environment.

  7. Avoid using harsh chemicals on any part of the microscope.

  8. Follow manufacturer guidelines for preventive maintenance to ensure long-term reliability.

 

Measurement & Weighing Instruments

Analytical Balance

Working Principle:

  1. An analytical balance works on the principle of electromagnetic force restoration or mechanical lever systems to measure mass with high precision.

  2. When a sample is placed on the pan, it causes a displacement. The balance generates an electromagnetic force to restore the pan to its original position.

  3. The magnitude of the electromagnetic force is proportional to the mass of the sample.

  4. The digital or dial display shows the measured mass, often up to 0.1 mg or 0.01 mg.

  5. Some balances use electronic sensors and load cells to enhance precision and reduce human error.

Uses:

  1. Accurate measurement of chemicals, reagents, and samples in laboratory experiments.

  2. Preparation of standard solutions and buffers in biochemical and chemical labs.

  3. Quantitative analysis in pharmaceutical, clinical, and research laboratories.

  4. Weighing small biological samples, powders, and solids.

  5. Quality control in industries requiring precise measurement of ingredients.

  6. Measurement of fine particulate matter in environmental studies.

Care:

  1. Place the balance on a stable, vibration-free, and level surface.

  2. Keep the balance clean and free from dust, powders, and moisture.

  3. Avoid touching the weighing pan with bare hands.

  4. Do not overload the balance beyond its maximum capacity.

  5. Use the balance in a draft-free environment to prevent fluctuations in readings.

  6. Always use weighing paper, containers, or boats to avoid direct contact with samples.

Maintenance:

  1. Calibrate the balance regularly using standard calibration weights.

  2. Perform internal calibration if the balance has an auto-calibration feature.

  3. Inspect the pan and sensors for dirt or damage; clean with a soft brush or cloth.

  4. Avoid exposure to corrosive chemicals near the balance.

  5. Keep records of calibration, maintenance, and any repairs.

  6. Service the balance periodically as recommended by the manufacturer.

  7. Ensure stable electrical supply and avoid voltage fluctuations to protect electronic components.

  8. Cover the balance with a dust cover when not in use.

 

Sterilization & Safety Equipment

Autoclave

Working Principle:

  1. An autoclave works on the principle of steam sterilization under pressure, using saturated steam at high temperature.

  2. Typical sterilization is done at 121°C under 15 psi pressure for 15–20 minutes (time may vary depending on load).

  3. The high-pressure steam denatures proteins and kills microorganisms, including bacterial spores.

  4. The autoclave chamber allows steam penetration into instruments, media, or other materials to achieve complete sterilization.

  5. Sterilization cycles are controlled by timers and thermostats or digital control panels.

Uses:

  1. Sterilization of surgical instruments, glassware, and laboratory equipment.

  2. Sterilization of culture media, reagents, and liquids in microbiology and biochemistry labs.

  3. Decontamination of biological waste before disposal.

  4. Preparation of sterile solutions and buffers.

  5. Sterilization of lab clothing, plasticware, and other consumables.

  6. Ensuring aseptic conditions in cell culture and molecular biology experiments.

Care:

  1. Do not overload the chamber; leave space for steam circulation.

  2. Use distilled water to prevent mineral deposits and scaling.

  3. Ensure all items are properly closed or wrapped to allow steam penetration.

  4. Avoid direct contact with hot surfaces; use heat-resistant gloves.

  5. Check the door seal and locking mechanism before each cycle.

  6. Keep the autoclave clean and free from spills or debris.

Maintenance:

  1. Regularly clean the chamber, trays, and door gasket.

  2. Check and replace worn or damaged seals, gaskets, and valves.

  3. Inspect the water reservoir and refill with distilled water as needed.

  4. Perform routine validation and biological spore testing to ensure sterilization efficiency.

  5. Check and calibrate pressure and temperature sensors periodically.

  6. Keep records of sterilization cycles, maintenance, and repairs.

  7. Follow manufacturer’s preventive maintenance schedule to prolong autoclave life.

  8. Ensure a stable electrical supply and proper ventilation to avoid damage.

Hot Air Oven

Working Principle:

  1. A hot air oven works on the principle of dry heat sterilization, using hot air circulated at high temperatures.

  2. Heat is generated by electric heating elements and distributed evenly inside the chamber.

  3. The oven relies on convection currents or a fan to circulate hot air for uniform heating.

  4. Sterilization is achieved by oxidation of cellular components, which kills microorganisms.

  5. Typical sterilization is done at 160–180°C for 1–2 hours, depending on the material and load.

Uses:

  1. Sterilization of glassware, metal instruments, and laboratory tools that can withstand dry heat.

  2. Drying of laboratory glassware, slides, and other equipment.

  3. Sterilization of powders, oils, and non-aqueous solutions.

  4. Decontamination of laboratory materials before use.

  5. Preparation of sterile containers and instruments for microbiology and biochemical experiments.

  6. Heat sterilization of certain laboratory plastics (if heat-resistant).

Care:

  1. Do not overload the oven; allow space for air circulation.

  2. Ensure that all items are dry before placing them in the oven.

  3. Keep the oven clean and free from dust or chemical spills.

  4. Avoid touching hot surfaces; use heat-resistant gloves.

  5. Monitor temperature settings to prevent overheating or burning of samples.

  6. Keep the door closed during operation to maintain uniform temperature.

Maintenance:

  1. Regularly clean the interior chamber and trays with mild detergent and water.

  2. Inspect the door seal and hinges for proper function.

  3. Check the heating elements periodically for damage or wear.

  4. Calibrate the temperature controller or thermostat regularly for accuracy.

  5. Keep a log of sterilization cycles, cleaning, and maintenance.

  6. Ensure proper electrical supply and avoid voltage fluctuations.

  7. Follow manufacturer’s preventive maintenance schedule for long-term reliability.

  8. Ensure good ventilation around the oven to prevent overheating of electrical components.

Laminar Air Flow Cabinet

Working Principle:

  1. A laminar air flow cabinet provides a contamination-free workspace by directing HEPA-filtered air in a uniform laminar flow.

  2. Air is drawn from the environment, passed through a pre-filter to remove large particles, and then through a HEPA filter to remove 99.97% of particles ≥0.3 µm.

  3. The filtered air flows in a unidirectional, laminar stream across the work surface, sweeping away airborne contaminants.

  4. The laminar flow can be horizontal (air flows from back to front) or vertical (air flows from top to bottom).

  5. The cabinet is designed to protect samples and work materials from contamination; some models also provide operator protection.

Uses:

  1. Preparation of sterile media, reagents, and culture plates.

  2. Aseptic manipulation of microbial, cell, and tissue cultures.

  3. Handling of biological samples to avoid contamination.

  4. Preparation of solutions for molecular biology experiments (e.g., DNA/RNA work).

  5. Pharmaceutical and clinical laboratories for sterile product preparation.

  6. Research laboratories to maintain aseptic conditions during experiments.

Care:

  1. Keep the cabinet clean and free from clutter to ensure smooth air flow.

  2. Disinfect the work surface and interior with 70% ethanol before and after use.

  3. Avoid blocking the air vents or HEPA filter.

  4. Wear appropriate personal protective equipment (PPE) such as gloves and lab coats.

  5. Work at least 6 inches inside the cabinet to maintain laminar flow integrity.

  6. Avoid sudden movements or rapid hand motions that may disturb the laminar flow.

Maintenance:

  1. Replace the HEPA filter periodically as per manufacturer recommendations or when air velocity drops.

  2. Check the blower, fan, and motor for proper operation.

  3. Inspect and clean pre-filters regularly to prevent dust accumulation.

  4. Calibrate airflow velocity and ensure uniform laminar flow using anemometers.

  5. Keep a maintenance log for cleaning, filter changes, and calibration.

  6. Avoid storing chemicals, reagents, or equipment inside the cabinet permanently.

  7. Ensure the electrical supply is stable and avoid overloading sockets.

  8. Follow the manufacturer’s preventive maintenance schedule for long-term efficiency and safety.

 

Bunsen Burner

Working Principle:

  1. A Bunsen burner works on the principle of combustion of gas (usually natural gas or liquefied petroleum gas) to produce a controlled flame.

  2. Gas enters through the inlet tube and mixes with air through adjustable air holes to form a combustible mixture.

  3. When ignited, the mixture burns to produce a flame whose temperature and intensity can be controlled by adjusting the gas flow and air supply.

  4. The flame can be luminous (yellow, cooler, with less air) or non-luminous (blue, hotter, with more air), depending on the air-to-gas ratio.

  5. The burner provides a high-temperature flame suitable for heating, sterilization, or combustion reactions in the laboratory.

Uses:

  1. Heating chemicals or solutions in test tubes, beakers, or flasks.

  2. Sterilization of inoculating loops, needles, or other small tools in microbiology.

  3. Combustion reactions in chemistry experiments.

  4. Demonstrations requiring flame, such as flame tests for metal ions.

  5. Evaporation of small amounts of liquid in laboratory experiments.

  6. Providing a controlled heat source for small-scale experiments.

Care:

  1. Ensure the gas supply is turned off when the burner is not in use.

  2. Place the burner on a stable, heat-resistant surface.

  3. Avoid flammable materials near the flame.

  4. Adjust the air and gas flow carefully to avoid excessive flame or backfire.

  5. Never leave the burner unattended while lit.

  6. Use proper lighting techniques with matches or a striker; avoid using hands near the flame.

Maintenance:

  1. Inspect the gas inlet, hose, and burner tube for leaks or damage regularly.

  2. Clean the burner tube to remove soot or blockages.

  3. Check the air holes for debris and ensure smooth airflow.

  4. Replace worn or damaged gas hoses immediately.

  5. Ensure proper connection between the burner and gas source.

  6. Keep a log of maintenance and inspections for safety.

  7. Follow the manufacturer’s recommendations for preventive maintenance.

  8. Ensure proper ventilation in the laboratory to avoid accumulation of gas.

Colony Counter

Working Principle:

  1. A colony counter works on the principle of visual detection and counting of microbial colonies on agar plates.

  2. It usually consists of a light source and a magnifying lens to illuminate and enlarge colonies.

  3. Some colony counters are manual, using a marking pen to tally colonies.

  4. Electronic or digital colony counters use a photodetector or camera system to detect and count colonies automatically.

  5. The counter provides accurate enumeration of microbial colonies for quantitative analysis in microbiology.

Uses:

  1. Counting bacterial or fungal colonies on agar plates in clinical, research, and industrial laboratories.

  2. Estimation of microbial load in water, food, or pharmaceutical samples.

  3. Monitoring growth of microorganisms in environmental and soil samples.

  4. Quality control in food and beverage industries.

  5. Evaluation of antibiotic efficacy by counting colonies in antimicrobial assays.

  6. Standardization of microbial cultures for experiments.

Care:

  1. Keep the colony counter clean and dust-free.

  2. Avoid spilling samples or agar on the counting surface.

  3. Handle plates carefully to prevent contamination or damage.

  4. Use appropriate lighting and magnification to avoid eye strain.

  5. Turn off the instrument when not in use to prolong lamp life (for illuminated models).

  6. Avoid touching sensitive electronic parts with bare hands.

Maintenance:

  1. Regularly clean the lens, stage, and light source with a soft cloth.

  2. Replace bulbs or LEDs if illumination is dim.

  3. Calibrate electronic counters periodically for accuracy.

  4. Inspect the counting surface or stage for scratches or damages.

  5. Keep a maintenance log including calibration, cleaning, and repairs.

  6. Ensure stable electrical supply to prevent damage to electronic components.

  7. Follow manufacturer guidelines for preventive maintenance and servicing.

  8. For digital counters, update software if applicable to maintain counting accuracy.

Deep Freezer

Working Principle:

  1. A deep freezer works on the principle of refrigeration using a vapor compression cycle.

  2. The refrigerant absorbs heat from the interior compartment and releases it outside through a condenser.

  3. The compressor circulates the refrigerant, maintaining low temperatures (usually −20°C to −80°C) inside the freezer.

  4. Thermostats or digital controllers regulate the temperature to ensure stable storage conditions.

  5. Uniform cooling and insulation prevent temperature fluctuations and preserve sample integrity.

Uses:

  1. Long-term storage of biological samples such as blood, plasma, serum, and tissues.

  2. Preservation of reagents, enzymes, and chemicals sensitive to temperature.

  3. Storage of vaccines, microbial cultures, and DNA/RNA samples in research labs.

  4. Maintaining temperature-sensitive pharmaceuticals and laboratory consumables.

  5. Storage of food samples in food science laboratories.

Care:

  1. Keep the freezer clean and free from ice buildup.

  2. Avoid frequent opening of the door to maintain stable temperature.

  3. Store samples in proper containers and avoid overloading.

  4. Ensure adequate air circulation inside the freezer.

  5. Use gloves when handling samples to prevent frostbite.

  6. Keep the freezer away from direct sunlight or heat sources.

Maintenance:

  1. Defrost periodically to remove ice accumulation.

  2. Check door gaskets and seals for proper closure; replace if damaged.

  3. Inspect compressor, condenser, and fans for proper operation.

  4. Calibrate temperature controllers periodically for accuracy.

  5. Keep a log of temperature readings, maintenance, and service.

  6. Ensure stable electrical supply; use voltage stabilizers if necessary.

  7. Clean condenser coils to maintain efficiency.

  8. Follow manufacturer’s preventive maintenance schedule to prolong freezer life.

Water Distiller

Working Principle:

  1. A water distiller works on the principle of distillation, separating water from impurities based on differences in boiling points.

  2. Water is heated in a boiling chamber to produce steam, leaving behind dissolved salts, minerals, and contaminants.

  3. The steam passes through a condenser, where it is cooled and converted back into purified water.

  4. The distilled water is collected in a separate container, free from most chemical and microbial contaminants.

  5. Some water distillers include activated carbon filters to remove odors or trace impurities after condensation.

Uses:

  1. Preparation of distilled water for laboratory experiments and reagent preparation.

  2. Sterile water for injections, culture media, and chemical solutions.

  3. Use in analytical instruments (e.g., spectrophotometers, pH meters) to avoid contamination.

  4. Preparation of buffers, dilutions, and standard solutions.

  5. General laboratory use where high-purity water is required.

  6. Cleaning or rinsing laboratory glassware to prevent residues.

Care:

  1. Use clean, preferably tap water, free from large particulates for distillation.

  2. Regularly clean the boiling chamber to remove scale or mineral deposits.

  3. Avoid overfilling the chamber to prevent water spillage or damage.

  4. Handle the unit carefully to avoid burns from hot surfaces or steam.

  5. Keep the collection container clean and covered to prevent contamination.

  6. Operate the distiller in a well-ventilated area to avoid excessive humidity accumulation.

Maintenance:

  1. Descale the boiling chamber regularly using mild acids or manufacturer-recommended descaling solutions.

  2. Clean or replace post-filters (if included) periodically.

  3. Inspect heating elements for proper operation and signs of corrosion.

  4. Check electrical connections and power supply to prevent short circuits or damage.

  5. Keep a log of cleaning, descaling, and maintenance activities.

  6. Follow manufacturer guidelines for preventive maintenance and servicing.

  7. Ensure proper cooling of the condenser to maintain efficiency.

  8. Store the distiller in a dry and dust-free area when not in use.