Analytical quality
Bioburden: The Scope of a Microbial Count
Bioburden and microbiological counts: Which population and sample fraction does the count cover?
Source editorial review:
Before interpreting the result
Which population and sample fraction does the count cover?
- Record preparation, medium, incubation and the count's unit.
- Distinguish organisms recoverable under the method from every possible contaminant.
- Record limits, inhibitor neutralization and method suitability when documented.
Bioburden and microbiological counts
A microbiological count depends on which organisms and conditions the method can recover. Sample, preparation, medium and assay conditions bound the observation. The result characterizes that procedure on that sample; it is not automatically an inventory of every possible microorganism or proof of sterility.
A reading case: what to check
Before comparing counts, inspect reported units and sample basis. Distinguish a numerical value from a result below the procedure's limit. If method or scope is absent, obtain that information before concluding batches are equivalent. A context-free number cannot reconstruct what was sought or what could be recovered.
What to preserve in the record
A bioburden count is not a general demonstration of sterility. The conclusion should name the conditions under which organisms were recoverable and countable.
Questions and answers
Which population and sample fraction does the count cover?
A microbiological count depends on which organisms and conditions the method can recover. Sample, preparation, medium and assay conditions bound the observation. The result characterizes that procedure on that sample; it is not automatically an inventory of every possible microorganism or proof of sterility.
What should the review record preserve?
A bioburden count is not a general demonstration of sterility. The conclusion should name the conditions under which organisms were recoverable and countable.