Sterility & Microbiological Testing

A purity figure tells you how much of a vial is the compound you ordered. It says nothing about what else is living in it. Sterility and microbiological testing covers whether a sample carries viable bacteria or fungi, and how heavy any microbial load is.

What the lab checks

A sterility test asks whether viable microorganisms are present at all. A bioburden (microbial enumeration) test counts them, typically as colony-forming units. Bacterial endotoxin is reported separately, because a sample can pass a sterility test and still carry endotoxin from earlier contamination. Sterility tells you what is alive now; endotoxin tells you what may have been alive before.

What a result means

A “no growth” or “below limit” result describes the specific sample received, under the conditions in the report. It is evidence about that vial and that batch — not a guarantee about other vials, and it does not survive an open seal or reconstitution with non-sterile water. Read every figure against the limit stated on the report.

To arrange testing, see submit a sample.