Sterility vs Purity
Purity and sterility answer different questions. Purity is a chemical measurement describing the proportion of detected material that corresponds to the target compound. Sterility is a microbiological determination of whether viable organisms are present. A high purity result does not establish sterility, and vice versa.
Published 2026-08-22 · Updated 2026-08-22 · Reviewed by the Lana editorial team
What does a sterility test involve?
Sterility testing incubates the sample, or a filtered portion of it, in growth media under defined conditions to detect viable microorganisms. It is a microbiological assay with its own methodology and limitations.
Why is the distinction so often confused?
A single percentage figure is easy to quote and easy to misread as an overall quality score. In reality, purity, identity, quantity, endotoxin and sterility are five independent questions requiring five different analyses.
Purity does not equal sterility
A 99% HPLC purity result does not establish sterility, absence of bacterial endotoxin, or suitability for administration to humans or animals under any circumstances.