Microbiology lab

The microbiology lab is a place where handling, culturing and manipulating the microorganisms will be done under controlled condition.

• The microbiology lab should be with good aeration and free from dust
• Bacteria and fungi are the common microbes being handled in all laboratories
• Most of the bacteria and fungi which are used for practical purpose are safe when handled properly
• The lab consists of chemicals, glasswares, microscopes and instruments for microbial techniques

Chemicals

The microbiology lab consists of all kinds of chemicals like inorganic salts, organic compounds, acids, alkali, organic solvents like alcohols, ether, acetones, etc. A polysaccharide, agar is a solidifying agent which is used to grow the microbes. The chemicals are mostly used to grow the microorganism under lab condition. Several dyes are used to colour (staining) the microbes so that can be seen under microscopes. The chemicals are also used to analyze the characters and chemical constituents of microbes. Ethanol (95% and 70%) is used to clean the floor for free of microbes. Cotton both non-absorbent and absorbent is very common usage.

Glasswares

The conical flasks, beakers, test tubes, slides, measuring cylinders, Petri dishes, reagent bottles, pipettes, burettes etc are the common glasswares used in microbiology lab. These are used to measure the volume, to prepare media for microorganisms, to grow the organism, etc. (Media refers the nutrient solution used to grow the microorganisms). Petri dish is specialized glassware used to grow the microbes without contamination. (Contamination - referring other microorganism in the environment).

Guidelines for handling:

A. Chemicals

• The chemicals should be stored based on the instructions given by the manufacturer (Normally 3 different temperatures are used to store the chemicals based on their nature; 25 - 30°C – room temperature; 4-0°C – refrigerator; - 15° ­- freezers of refrigerator or deep freezer)
• Don’t inhale or taste the chemicals (even sugar)
• Use always dried spatula for taking the chemicals
• In case of acids and phenol, as corrosive nature, handle properly (acid resistant gloves)
• Some chemicals are carcinogenic, for which direct handling should be avoided (gloves)
• Some chemicals are mutagenic, for which maximum care should be taken (gloves)
• Inhaling solvents like chloroform, ether lead to unconsciousness
• Some chemicals are hydroscopic (they absorb water from air and become slimy or solid). Close air tightly after use.
• Avoid spilling water in the chemical bottles leads lose of property.

B. Glasswares

• Use always clean and dry glasswares for microbiology purpose
• Sterilize properly before use
• Touching the hot glasswares leads burning injury. Use towels or gloves to handle
• Clean the glasswares with soap solution and rinse with distilled water after use
• Use driers (60 – 80°C) to dry the glasswares

C. Instruments

• Clean the microscopes with dry tissue papers and cover the microscopes free of dust.
• Know the methodology and principle of any instrument before use
• Read the manuals supplied by the manufacturer before handling any instrument
• Most of the instruments are electrical and proper care should be taken to handle without shock
• In Autoclave, high pressure will be generated. So Don’t allow the pressure to build above the red mark
• The steam released from autoclave is above 100°C which may cause burning injury
• Sudden releasing of pressure in the autoclave may be avoided which leads to shatter the glasswares or spill of liquid from container to outside.
• The laminar flow chamber contains UV lamp for sterilization. So Be sure to turn off the UV lamp before working.
• The hot air oven will have about 180°C in side the chamber. So be sure to touch the inner side and doors of oven.
• Please avoid weighing in the electronic balance above the maximum limit, which may lead to damage the instrument or reduce its precision
• The pH meter – probe should be washed with distilled water before and after use.
• Don’t keep airtight materials in microwave oven , which may lead to explosion

D. Microbes observation

Don’t touch the microbes grown in a flask or in plates

Microbes should be observed in unopened containers only

Don’t use mouth to pipette out the microbial solution

Don’t keep the plates containing microbes (especially fungi ) near the face which may irritate the eye and skins

Record the observations with all the factors used for calculation in the lab note book and tabulate.

E. Waste disposal

Don’t through the waste materials openly in the lab which may leads to contamination

The tissue papers, paper towels, filter papers should be collected and disposed

Don’t through the microbes containing plates directly to the wastes which may further multiply and contaminate the environment

The microbes grown plates should be collected in sterilizable polybag and sterilize by autoclave and dispose them.

Don’t through the solid wastes in the sinks which may lead to blocking

Don’t pour the microbial culture in solution directly to the sink, which may further multiply in the waste water and cause health hazards

The microbial solutions should be collected in a container and autoclaved and disposed them.