What is microbiology?
It’s a fascinating branch of science that plays a crucial role in understanding the unseen world of microorganisms. From bacteria to fungi, these microscopic life forms are all around us - on surfaces, in the air, and even on our skin. While many microbes are harmless, some can cause illness, which is why it's essential to handle them with care in any microbiology experiment. Proper safety protocols for microbiology, sterilising or destroying equipment after use and incubating at safe temperatures, are fundamental to ensuring safe and successful experiments.
Top 10 Safety Tips:
1. Treat all microorganisms as potential pathogens even when working with stock cultures and conditions that do not grow strains that are pathogenic to humans.
2. Purchase new stock cultures annually or reconstitute from frozen, this will minimise contamination and maintain healthy viable stock. Sub culture these on receipt to prevent contamination of the original culture
3. Always wear suitable PPE when handling or dealing with microbiological samples.
4. Disinfect work areas before and after use, using 70% alcohol solution or our recommended Virkon disinfectant.
5. Wash your hands before and after with a disinfectant soap, even if you have been wearing gloves.
6. Ensure all the equipment and materials required are sterile. Media, tubes, pipettes, loops and petri dishes. All media and discarded items should be autoclaved at 121C for 15mins.
7. When dispensing media into petri dishes, use a fume cupboard where possible. This reduces the risk of contaminating your agar, but also reduces the risk of inhaling any airborne microorganisms from your culture. Or work within 1m of a Bunsen flame.
8. Never mouth pipette, use bulbs or pipetting devices for any liquid dispensing.
9. Never eat or drink in the laboratory while working with bacteria. Keep your hands away from your mouth and cover all cuts or sores. Sterile gloves may be worn.
10. Label everything clearly with names and dates on the base of the plate-if you accidently lose the lid If they are hazardous, remember to label with the relevant hazardous information.
KS3 Experiment - Growing Bacteria on Agar Plates:
Try this simple yet engaging KS3 experiment, which covers how to culture bacteria in the laboratory by growing bacteria on agar plates. Ignite your students’ curiosity.
Students will learn what is microbiology by swabbing everyday surfaces like desks, door handles – or even their own mobile phones. They will then observe the growth of bacteria and fungi after several days, giving them a visual understanding not only of how microorganisms grow, but also of how commonly they are found on surfaces we might otherwise think are clean!
Materials:
1. Prepare Work Area: Wear sterile gloves and clean your workspace with disinfectant to reduce risk of contamination. Light a Bunsen.
2. Label the Agar Plates: Use a marker to label each agar plate on the bottom with the surface you are swabbing (e.g., door handle, desk, unwashed hand, etc.). Draw a line to divide the agar plate into 2 labelling both halves with area swabbed.
3. Swab Surfaces: Take a sterile cotton swab and gently roll the swab across your chosen surface, such as a desk, door handle, or your hand.
4. Transfer Swab to Agar Plate: Gently roll the swab across the surface of the agar plate in a zigzag pattern to transfer the bacteria. Be gentle, and careful not to damage the agar with your swab. Dispose of the swab immediately into a beaker of disinfectant.
5. Prepare a Comparison Plate (Optional Extension): Use hand sanitiser or soap on one hand and swab the surface again. With a new swab. Roll this swab onto a separate agar plate or the other half of the agar plate to compare bacterial growth.
6. Seal the Agar Plates: Seal each agar plate with tape in an ‘X’ pattern, across top and bottom of the closed plate. This will prevent any more microorganisms from entering the plate, but still allowing oxygen to circulate.
7. Incubation: Place the agar plates upside down (to avoid condensation dripping onto the surface of the agar) in an incubator set to 21-25°C or in a warm, dark location at room temperature.
8. Observe Growth: After 5-7 I would go with 2-3 days, check the plates for visible growth of microorganisms. Record observations, including colony colour, appearance, size, and number. Can you identify which colonies are from bacteria and which are fungi? Do not open the plate.
9. Compare Plates: Describe differences in bacterial growth between surfaces, and between clean and unclean surfaces (if using the extension with hand sanitiser or soap).
10. Disposal: Once the experiment is complete, seal the plates in a bag and disinfect the area. Dispose of the plates as biological waste following school protocol.
Please contact your local Select Education territory sales manager, who will be willing to support you with expert knowledge, tailored recommendations, and practical solutions for your lab needs.
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