Begin with sample identity
Verify the product or location, lot and collection information. Results from different samples should not be treated as a continuous trend unless their collection and testing context are comparable.
Counts and detection statements
CFU is a colony-forming-unit result under the method conditions. Detected or not-detected results relate to a named target and test portion. A value below the reporting limit is different from proof that no organisms exist.
Apply the right criteria
The agreed specification, product category and intended use determine how a result is assessed. Do not transfer a limit from one matrix, route of use or collection basis to another without reviewing its applicability.
Define the next question
An unexpected finding may call for confirmation, isolate identification, comparison samples or a review of collection and process records. The analytical result supports that decision; it does not establish every cause on its own.
Related testing & guidance
Technical & service references
Vanguard microbiology service menuFDA: Bacteriological Analytical ManualUSP: General Chapter <61>Source review: November 8, 2026. The agreed method and project scope govern the testing.