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Biology LibreTexts

Microbiology Lab Safety Instructions

  • Page ID
    15951
  • The instructions below are designed to keep you safe in the laboratory. Please read them carefully. If you have any questions about safe laboratory practices, ask your instructor.

    1. No eating, drinking or smoking at any time. Do not bring food or drink items into the lab. Avoid all finger/hand-to-mouth contact.

    2. A lab coat must be worn at all times in the microbiology laboratory. You will not be allowed to participate in the lab without one.

    3. Follow all directions given by the instructor. Bring any safety concerns to the attention of the instructor.

    4. Come to lab on time and prepared for that day's experiments.

    5. Wash hands, and wipe down bench area with disinfectant prior to working. Before you leave the lab for the day wipe down your bench area with disinfectant and then wash your hands. Wash your hands at any time during the lab if you think you may have contaminated them. Wipe any surfaces or equipment with disinfectant immediately if you suspect contamination with living cultures.

    6. Loose clothing and long hair must be tied back while working to avoid burning with open flames or inadvertent contamination.

    7. Open-toed shoes (sandals, flip-flops etc.) cannot be worn in lab.

    8. Use care with the Bunsen burners. Keep paper, alcohol and other flammable items away from the open flame.

    9. Treat all living cultures of microorganisms (bacteria, yeast, etc.) as potential pathogens. Avoid spilling or spreading the microorganisms. Place all used materials in the appropriate waste containers designated for cultures (to be autoclaved). Use the techniques specified by the instructor for handling microorganisms. If there is a spill notify your instructor immediately.

    10. Know where fire extinguishers and safety equipment are located in the lab.

    11. To prevent contamination of these articles, books, coats, backpacks, etc. (anything you do not need for the Micro lab) must be placed in the designated area and should not be kept at the laboratory table.

    12. Make sure to carefully read through the entire procedure before beginning an experiment in the lab. This will help prevent you from making mistakes that could compromise your safety

    Notes:

    • Since many laboratory procedures are carried over to the next week, make sure you bring previous lab write-ups with you to the following lab.
    • For supplementary color pictures of media, microorganisms, videos, etc., see the Blackboard Review site. Instructions for signing up for this site are provided in the syllabus.

    Instructions for Good Laboratory Practice and Care of Laboratory Equipment 

    Correct use and care of the laboratory equipment is considered a fundamental part of good laboratory technique. All students working in the microbiology laboratory are responsible for maintaining equipment and materials in proper working condition.

    Please read over and follow the instructions listed below:

    Microscopes

    The most critical (and most expensive) piece of equipment in the microbiology laboratory is the microscope. If you expect to see specimens through the microscope, it must be kept clean and in good condition. You must use the microscope assigned to your seat. Instructions for the use and care of the microscope can be found in Lab 1 of the lab manual. Report any problems with your microscope to your instructor.

    Inoculating loops and inoculating needles

    Inoculating loops and needles are used to transfer bacteria into and from culture media. Inoculating loops have a loop at the end, while inoculating needles end in a point. Inoculating loops are the most common method of transferring bacteria. Inoculating needles are used when stabbing into a medium during specific inoculation procedures, or when it is necessary to pick up a small amount of bacteria from one colony on an agar plate without contacting bacteria in other colonies.

    Bunsen burners

    A Bunsen burner is a source of open flame that is used to sterilize loops and needles, as well as flaming the lips of test tubes during inoculations. You must always take great care when operating a Bunsen burner!

    To light the Bunsen burner, turn the handle of the valve so it is in line with the tubing connecting the Bunsen burner to the gas. Using a striker or a BBQ lighter, light the Bunsen burner. If the Bunsen burner does not immediately light, turn off the gas and determine the cause of the problem. NEVER leave the gas on if the Bunsen burner is not lit. DO NOT lean over the Bunsen burner while lighting it.

    Once the Bunsen burner is lit, be careful to keep all flammable items, including lab coats, hair, shirt sleeves, scarves, tissues, alcohol, etc. away from the flame. When the Bunsen burner is not actively in use it should be kept in the pilot setting for safety. If you smell gas at any time, check to make sure that the Bunsen burner is still lit. If the flame goes out at any time, TURN OFF THE GAS. When you are finished using the Bunsen burner, be sure to return it to the pilot setting before turning off the gas.

    Before leaving the lab, make sure that the gas is off (handle of the valve perpendicular to the tubing connected to the Bunsen burner).

    Microscope slides

    Any disposable glass slides should be discarded in the sharps container. Do not discard glass slides in the waste cans.

    Petri dishes and test tubes

    All materials used for handling or culturing microorganisms are to be disposed of as follows: test tubes placed in racks in a bin for autoclaving; petri dishes in the other bin for autoclaving and disposal.

    Spillage

    Any living culture material that is spilled, either on tables or on the floor, is to be treated immediately with disinfectant and cleaned up with paper towels. Notify the instructor of any spills. The paper towels that you use to clean up the spill should be placed in the bin with the petri dishes for autoclaving.

    Prepared slides

    Prepared slides that are used during the semester must be returned clean to the trays from which they were taken.

    Cleanliness of the room

    Any papers on the floor at the end of the laboratory period are to be picked up and discarded in the wastebasket. The same is true for your laboratory bench area.

    VERY IMPORTANT!

    DO NOT throw plates, tubes, swabs, slides, pipets, pipet tips, broken glass, etc. into the regular garbage. These items need to be disposed of properly. Throwing potentially contaminated items into the regular garbage is a safety issue for students, instructors, lab techs and the cleaning staff. If these items are found in the regular garbage the ENTIRE BAG OF GARBAGE must be autoclaved before disposal. If you are unsure about where an item should go, always ask your instructor.