Introduction to Microbiology and Laboratory Safety
Introduction
This domain introduces the scope of microbiology and the safety culture of a clinical or teaching laboratory. The exam tests biosafety levels, standard precautions, personal protective equipment, sharps and spill management, waste segregation, and incident documentation.
Core rules
- Treat all clinical samples as potentially infectious and apply standard precautions to blood, body fluids, and cultures.
- Match containment to risk: BSL-1 for non-pathogenic teaching strains, BSL-2 for most clinical specimens, and higher levels only for specific agents.
- Wear gloves, gown, and eye protection when splashes are possible; remove PPE before leaving the bench and perform hand hygiene.
- Never recap, bend, or break needles; place sharps directly into a puncture-resistant container.
- Segregate waste at source: infectious waste for autoclave or incineration, sharps into sharps containers, chemicals separately.
- Decontaminate benches before and after work with a suitable disinfectant and allow the stated contact time.
Worked example
A blood culture bottle breaks on a BSL-2 bench. Stop work, warn others, and do not pick up glass with gloved hands. Cover the spill with absorbent paper, pour freshly prepared 1% sodium hypochlorite around and over it, and leave for at least 30 minutes. Pick up glass with forceps into a sharps container, wipe the area, discard absorbent as infectious waste, and report the incident.
Traps
Do not use alcohol as the primary disinfectant for a large blood spill; it is flammable and may fix protein. A spill kit is useless if its location and expiry are unknown. Do not leave a broken container on the bench while looking for a supervisor; contain first, then report.