Quality Assurance and Biosafety
Domain focus
Quality assurance and biosafety questions test internal QC rules, external quality assessment, biosafety levels, personal protective equipment, spill management and safe waste handling in Cambodian laboratories.
Core rules
- Run two QC levels and apply Westgard rules before releasing patient results.
- 1-2s is a warning; 2-2s, R-4s, 4-1s and 10x indicate rejection and investigation.
- Participate in external quality assessment and investigate unacceptable results.
- Match biosafety practice to risk group: BSL-2 for most routine bacterial and viral work, with negative-pressure and respiratory protection for aerosol-generating TB procedures.
- Use a biological safety cabinet correctly: work deep inside, minimise airflow disruption, and decontaminate after spills.
- Segregate sharps and infectious waste at the point of generation.
Worked example
A Levey-Jennings chart shows two consecutive glucose QC values below -2 SD on the same level. The 2-2s rule is violated, so patient results are rejected. The technologist checks reagent expiry, calibration and the electrode, repeats QC, and only releases results after acceptable correction. A single value outside 2 SD would be a 1-2s warning, not automatic rejection.
Traps
- Treating 1-2s as rejection without further rule violation.
- Working in a biosafety cabinet with the sash raised too high.
- Recapping needles or leaving sharps at the bench.
- Ignoring an unacceptable EQA result because internal QC was normal.