Quality Control
Specification
Research use only. For in vitro research use only. Not for human or animal consumption. Not for human consumption, medical use, or personal application.
A specification is the set of acceptance criteria a material must meet before use: which attributes are examined, by which method, within which limits. Written in advance, it is a decision rule rather than an observation. The measured result for a lot lives on its certificate; the limit that result is judged against lives in the specification.
A limit is not a result
"Not less than 98.0% by HPLC" is a specification. "98.7%" is a result. The first applies to every lot; the second measures one. A pass means something only if the limit was fixed before the result was read.
A result well inside a limit says nothing about the next lot: a limit is what a supplier commits to, not what its process typically delivers. A result inside the supplier's limit but outside yours still fails — the Certificate of Analysis has not changed, your criteria have.
What a usable specification names
Every line needs an attribute, a method and a limit, because a limit without a method is unenforceable. A purity criterion can be met or missed depending on gradient and wavelength, so name the HPLC conditions.
It should also say what is out of scope. Attributes such as sterility and endotoxin often sit outside a research lot's testing scope, and silently assuming them produces an indefensible file.
Frequently asked questions
- Who sets it, the supplier or the laboratory?
Both, separately. A supplier specifies what it releases against; a laboratory specifies what it accepts. Where the two differ the stricter governs, and the qualification record should show which was applied.
- Does a Certificate of Analysis contain the specification?
It often prints the supplier's limits beside the results, which is useful but is not your specification. Copy the limits you intend to apply into your own document.
- How specific does a limit need to be?
Specific enough that two people reach the same decision. Numeric limits with a named method achieve that; wording such as "high purity" cannot support an acceptance or a rejection.
Updated 2026-06-01