Read the result together with the method, units, limit and suitability evidence.
Start with what the conclusion addresses
FDA’s endotoxin guidance discusses testing methods, acceptance criteria and their use with actual samples. A report should be read with its test identity, method version, units and acceptance criterion. Endotoxin and sterility testing address different questions.
Dilution and interference affect interpretation
A sample matrix can inhibit or enhance an assay response. FDA discusses inhibition/enhancement testing, maximum valid dilution and retesting. A less-than result is best interpreted alongside the dilution, detection capability and evidence that the method was suitable for the sample.
Sources [1]
Keep the record that explains the result
Keep the report and sample identifiers, date, method, units and suitability information together. Before comparing reports, check that they use a comparable basis. This reading framework does not set a universal limit or extend a result beyond its stated scope.
Original sources
These notes explain public references; they do not replace sample-specific testing or case-specific professional judgment.