14 Common Glassware used in A Microbiology Laboratory

Microbiology laboratories require well-built rooms that are equipped with tools, glassware and equipment. Test tubes, culture tubes, Petri dishes and Erlenmeyer flasks are the most important types of glassware in a microbiological lab.

1. Test tube

Test tube is a common laboratory apparatus used for holding, mixing and heating small amount of chemicals. It is usually made up of glass or transparent plastic. It has cylindrical shape with open upper end and closed rounded bottom.

The following are the important points of test tube-

Material- Test tube is generally made up of glass or plastic. Glass test tube may be made up of borosilicate glass which can resist high temperature.

Plastic test tube- Plastic test tube is used mainly in biological work. It is disposable and does not break easily.
Shape- It is thin and cylindrical in shape. It has open mouth and rounded bottom.
Rounded bottom- The rounded bottom helps in easy mixing of solution. It also helps in pouring the contents with less loss.

Mouth of test tube- Some test tubes have flared lip for easy pouring. Some may have screw cap or glass stopper for sealing.
Use in chemistry- It is used in chemical laboratory for holding chemicals, mixing solutions and carrying out small reactions.
Heating- Glass test tube is used for heating chemicals. It can be heated directly over flame when made up of heat resistant glass.

Observation of reaction- The transparent wall helps to observe colour change, gas formation or precipitate formation during reaction.
Use in biology- In biological science, test tube is used as culture tube. It is used for growing microorganisms and handling biological specimens.
Use in clinical laboratory- Sterile test tubes are used for collecting and storing blood, urine and other body fluids. These tubes may contain rubber stopper and some additives for preserving the sample.

Test tube, culture tube and screw-capped tubes

2. Petri dish

Petri dish is a shallow cylindrical laboratory dish used for growing microorganisms. It is used for culture of bacteria, fungi and other small organisms. It is made up of glass or transparent plastic.

The following are the important points of Petri dish-

Structure- Petri dish has a flat bottom and vertical side wall. It has a lid which loosely covers the dish.
Material- It is usually made up of glass or plastic. Glass Petri dish can be sterilized and used again.

Plastic Petri dish- Plastic Petri dish is disposable. It is used when contamination has to be avoided.
Lid- The lid covers the upper part of the dish. It helps to reduce contamination and also allows some air exchange.
Culture medium- Nutrient medium is poured into the Petri dish. Agar is commonly used to make the medium solid.

Microbial culture- Microorganisms are inoculated on the agar surface. Then the dish is incubated for growth of colonies.
Observation- It is used to observe colony shape, colour, size and growth pattern of microorganisms.
Experimental use- Petri dish is used to study effect of different conditions on microbial growth. Temperature, chemicals and nutrients can be tested.

Antimicrobial test- It is used for testing antimicrobial drugs. Zone of inhibition around the chemical shows inhibition of microbial growth.
History- Petri dish was developed by Julius Richard Petri in 1887. He was working as an assistant of Robert Koch. It became an important apparatus in microbiology.

3. Beakers

Beaker is a common laboratory apparatus used for holding, mixing, heating and transferring liquids. It is usually cylindrical in shape with flat bottom. It has a small spout for pouring liquid.

The following are the important points of beaker-

Material- Beaker is generally made up of glass, plastic or metal. Glass beaker may be made up of borosilicate glass.
Shape- It is cylindrical in shape. It has a wide mouth and flat bottom.
Flat bottom- The flat bottom helps the beaker to stand properly on lab bench or hot plate.

Spout- A small spout is present at the rim. It helps to pour liquid easily and reduces spilling.
Graduation marks- Many beakers have volume marks on the side wall. These marks show approximate volume only.
Accuracy- Beaker is not used for exact measurement of liquid. For accurate measurement, graduated cylinder or volumetric flask is used.

Mixing of solution- It is used for mixing chemical solutions. The wide mouth and straight side wall help in easy stirring.
Heating of liquid- Borosilicate glass beaker can be used for heating liquids. It can tolerate thermal shock better than ordinary glass.
Transfer of liquid- It is used for transferring liquid from one container to another. The spout helps controlled pouring.

Griffin beaker- It is also called low form beaker. Its height is about 1.4 times of its diameter and it is used for general laboratory work.
Berzelius beaker- It is a tall form beaker. Its height is about double of its diameter and it is commonly used in titration work.
Crystallizer beaker- It is used in crystallization process. It is usually wide and may not have measurement markings.

4. Pipette

Pipette is a laboratory instrument used for measuring and transferring definite volume of liquid. It is used in chemistry, biology and medical laboratory. It is important where accurate liquid handling is required.

The following are the important points of pipette-

Function- Pipette is used to take and transfer a measured volume of liquid from one container to another.
Accuracy- It is designed to deliver accurate volume of liquid. So, it is used in experimental works where correct volume is important.

Types- Pipettes are available in different types and sizes. Each type is used according to the volume and purpose of work.
Volumetric pipette- It is used to deliver one fixed volume of liquid. It gives high accuracy.
Graduated pipette- It has graduation marks along its length. It is used to measure and transfer different volumes of liquid.

Micropipette- It is used for very small volume of liquid. It is commonly used in microliter range.
Pasteur pipette- It is a simple glass or plastic pipette. It is used for transferring small amount of liquid without exact measurement.
Electronic pipette- It is controlled electronically. It is used for better precision and repeated pipetting work.

Sample preparation- Pipette is used for measuring and transferring liquids during analytical procedure.
Titration- It is used to deliver accurate volume of titrant or solution during titration.
Cell culture- It is used for transferring media, reagent and cells in biological work.

Molecular biology- It is used for handling small volume of DNA, RNA, enzymes and other reagents.

5. Erlenmeyer flasks

Erlenmeyer flask is a laboratory glassware used for mixing, heating and holding liquids. It is also called conical flask. It has conical body, flat bottom and short narrow neck.

The following are the important points of Erlenmeyer flask-

Shape- It has a conical body with broad base and narrow neck. This shape helps in mixing liquid by swirling.

Flat bottom- The flat bottom helps the flask to stand properly on lab bench or hot plate.
Narrow neck- The narrow neck reduces spilling during mixing. It also helps to fit stopper, cotton plug or other closure.
Material- It is usually made up of glass or plastic. Glass Erlenmeyer flask can be used for heating and sterilization.

Capacity- It is available in different sizes and capacities. The size is selected according to the volume of liquid.
Mixing- It is used for mixing solutions by swirling. The liquid can be mixed without much chance of spilling.
Heating- It is used for heating and boiling liquids. The narrow upper part helps vapour to condense and reduces solvent loss.

Titration- It is used in titration work. The solution can be swirled easily during addition of titrant.
Filtration- The narrow mouth can hold filter funnel. So, it is also used during filtration process.
Microbial culture- It is used in microbiology for growing microbial cultures. It may be closed with cotton plug or vented closure.

Shaking culture- Erlenmeyer flask is used in shaking incubation. The shape helps in aeration and mixing of culture medium.

6. Volumetric flasks

Volumetric flask is a laboratory glassware used for preparing exact volume of solution. It is calibrated to contain a fixed volume of liquid at a definite temperature. It is commonly used in analytical chemistry.

The following are the important points of volumetric flask-

Shape- It has flat bottom, pear shaped body and long narrow neck. The narrow neck helps in accurate adjustment of liquid level.

Calibration mark- It has one calibration mark on the neck. This mark shows the exact volume that the flask can contain.
Temperature- Volumetric flask is usually calibrated at 20°C. If temperature changes, the volume may not remain exact.
Material- It is made up of glass or plastic. Glass flask is used for chemical work and sterilization.

Plastic flask- Plastic volumetric flask is light in weight and does not break easily.
Stopper or cap- It has stopper or screw cap for closing the mouth. It helps to seal the liquid inside the flask.
Standard solution- It is used for preparing standard solutions. It helps to make solution of accurate concentration.

Dilution- It is used for dilution of stock solution. The solution is made up to the calibration mark with solvent.
Titration work- It is used in chemical analysis and titration related work. It gives accurate volume for preparation of solution.
Meniscus reading- The bottom of meniscus should be adjusted exactly on the calibration mark. The reading should be taken at eye level.

Accuracy class- Class A volumetric flask gives higher accuracy than Class B flask. It is used when more precise work is required.

7. Glass spreader

Glass spreader is a laboratory glassware used for spreading microbial culture on the surface of agar plate. It helps to distribute bacteria or fungi evenly on Petri dish. It is commonly used in microbiology laboratory.

The following are the important points of glass spreader-

Material- Glass spreader is usually made up of heat resistant glass. Borosilicate glass is commonly used because it can be sterilized easily.

Shape- It is made as a smooth glass rod. The end may be rounded or flattened for proper spreading.
Function- It is used to spread microbial suspension evenly on agar surface. It helps to get uniform growth of colonies.
Use in microbiology- It is used for spreading bacterial and fungal cultures on agar plates.

Colony counting- It helps to distribute microorganisms separately on plate. So, colonies can be counted and studied properly.
Sterilization- Glass spreader must be sterilized before use. Flaming or autoclaving is done to prevent contamination.
Handling- It should be cooled after flaming before touching the agar surface. Hot spreader may kill microorganisms or damage the agar.

8. Haemocytometer

Haemocytometer is a special glass slide used for counting cells in a liquid sample. It has a marked grid on its surface. It is mainly used under microscope for cell counting.

The following are the important points of haemocytometer-

Material- Haemocytometer is usually made up of glass. It is a thick and specially prepared glass slide.
Grid- It has a precisely etched grid of small squares. These squares are used for counting cells in fixed area.

Chamber depth- It has a fixed chamber depth, usually 0.1 mm. This gives a known volume for counting.
Function- It is used to count cells present in a liquid sample. The number of cells counted is used to calculate cell concentration.
Blood cell counting- It is used in clinical laboratory for counting blood cells.

Cell culture work- It is used in research laboratory for counting cells in cell culture.
Microbial count- It may be used for counting microbial cells in suspension.
Sample loading- A small amount of cell suspension is placed on the slide. A cover glass is placed over the counting chamber.

Microscopic observation- The cells present in selected grid squares are counted under microscope.
Calculation- The counted cells are used to calculate the number of cells per unit volume of sample.

9. Ocular micrometer

Ocular micrometer is a small glass disc used in the eyepiece of microscope. It has a scale etched on it. It is used for measuring small microscopic objects.

The following are the important points of ocular micrometer-

Material- Ocular micrometer is usually made up of glass. It has a fine measurement scale marked on it.
Position- It is placed inside the eyepiece of microscope. So, the scale is seen along with the microscopic object.
Function- It is used to measure the size of microscopic structures. Cells and other minute objects can be measured by using it.

Scale- The scale has divisions but these divisions do not show actual length directly. So, calibration is required before measurement.
Calibration- Ocular micrometer is calibrated with stage micrometer. This helps to know the actual distance of each division.
Use in biology- It is used in biological research for measuring cell size and other small structures.

Use in material research- It is also used in material study for measuring minute particles or structures.
Microscopic measurement- After calibration, the object is viewed under microscope. The number of ocular divisions covered by the object is counted and actual size is calculated.

10. Stage micrometer

Stage micrometer is a microscope slide used for calibration. It has a very fine scale etched on its surface. It is used to calibrate the ocular micrometer.

The following are the important points of stage micrometer-

Material- Stage micrometer is usually made up of glass. It has a finely etched measurement scale.
Structure- It looks like a microscope slide. The scale is present at the centre of the slide.
Function- It is used for calibration of ocular micrometer. It helps to measure microscopic objects accurately.

Scale- The scale has known divisions. These divisions are usually given in micrometers.
Calibration- Stage micrometer is placed on the microscope stage. The ocular micrometer scale is compared with the known scale of stage micrometer.
Measurement- After calibration, the value of one ocular division is calculated. Then microscopic objects can be measured correctly.

Use in research- It is used in biological and material research. It helps in measuring cells, particles and other minute structures.
Use in clinical laboratory- It is used in clinical laboratory where exact measurement of microscopic features is required.

11. Glass Rods

Glass rod is a simple laboratory apparatus used for stirring and mixing liquids. It is also called stirring rod. It is made up of solid glass.

The following are the important points of glass rod-

Material- Glass rod is usually made up of borosilicate glass. It can resist heat and many chemicals.
Shape- It is a straight solid glass rod. It is generally slightly longer than a drinking straw.
Ends- The ends are rounded. This prevents scratching or breaking of glassware during use.

Mixing- It is used for mixing chemicals and liquids in beaker or other container.
Stirring- It is used for stirring solution during preparation of mixture. It helps to dissolve solute properly.
Decanting- It is used during decanting of liquid. The liquid is poured along the glass rod to control flow and reduce spilling.

Crystallization- It can help in crystallization. Scratching the inner wall of container with glass rod may start crystal formation.
Spreading- It is used for spreading substances on solid surface. It may be used for spreading bacterial culture on solid medium.
Static electricity- It is used in physics experiment for showing static electricity. It is rubbed with silk or other material to produce charge.

Cleaning- Glass rod should be washed after use. It should be kept clean to avoid contamination of solution.

12. Microscope Slides and Cover Slips

Microscope slide and cover slip are used for preparing specimen for microscopic observation. They help to hold the specimen properly under microscope. Both are usually made up of glass or sometimes plastic.

The following are the important points of microscope slides and cover slips-

Microscope slide- Microscope slide is a thin and flat rectangular piece. It is used to keep the specimen for observation.
Material of slide- It is usually made up of glass. Sometimes plastic slides are also used.
Size of slide- The common size of microscope slide is about 75 mm × 25 mm.

Function of slide- It provides a clear and stable surface. The specimen can be seen through it under microscope.
Cover slip- Cover slip is a small and thin piece of glass or plastic. It may be square or rectangular in shape.
Position of cover slip- It is placed over the specimen on the microscope slide. It covers the specimen during observation.

Protection- Cover slip protects the specimen from dust, contamination and damage.
Flattening of specimen- It helps to flatten the specimen. So, the specimen becomes thin and easy to observe.
Image clarity- Cover slip reduces optical distortion. It helps to get clear microscopic image.

Use- Microscope slide and cover slip are used in biology, microbiology and clinical laboratory for observing cells, microorganisms and other small specimens.

13. Burettes

Burette is a laboratory instrument used for dispensing measured amount of liquid. It is mainly used in titration. It helps to add liquid slowly and accurately.

The following are the important points of burette-

Structure- Burette is a long and narrow tube. It has graduation marks along its length.

Material- It is usually made up of glass. Borosilicate glass is commonly used because it can resist chemicals and temperature change.
Stopcock- A tap or stopcock is present at the lower end. It controls the flow of liquid from the burette.
Graduation marks- It has fine calibration marks on the tube. These marks are used to measure the volume of liquid delivered.

Function- It is used to dispense known volume of liquid. The liquid can be added drop by drop by using stopcock.
Use in titration- Burette is mainly used in titration experiment. It is used to add titrant slowly into the solution.
Accuracy- It gives accurate volume reading. So, it is important in quantitative analytical work.

Handling- Burette should be kept vertical during use. The reading should be taken at eye level to avoid error.

14. Glass Funnels

Glass funnel is a laboratory tool used for transferring liquid or powder from one container to another. It has a wide opening at the upper part and a narrow stem at the lower part. It helps to pour materials without spilling.

The following are the important points of glass funnel-

Material- Glass funnel is usually made up of heat resistant glass. Borosilicate glass is commonly used because it can resist heat and chemicals.

Shape- It has a wide mouth at the top. It has a narrow stem or spout at the bottom.
Wide opening- The wide upper opening helps in easy pouring of liquid or powder.
Narrow stem- The narrow stem guides the liquid into a container with small mouth. It reduces spilling during transfer.
Transfer of liquid- It is used for transferring liquids from one container to another.
Transfer of powder- It is also used for transferring powders into narrow mouth containers.
Filtration- It is used with filter paper during filtration. The filter paper is placed inside the funnel and liquid is poured through it.
Decanting- It is used for decanting chemicals and solutions safely. It helps to control the flow of liquid.
Cleaning- Glass funnel should be washed properly after use. It should be kept clean to avoid contamination.