Analytical workflow

Laboratory testing and independent verification

Testing is layered deliberately: in-house analysis catches problems early and cheaply, independent verification removes the conflict of interest inherent in a producer grading its own output.

Last updated August 5, 2026Analytical methodsReviewed by the PrimeGen Co. laboratory documentation team

Two layers, different purposes

In-house analysis is diagnostic. It runs during and immediately after purification, guides fraction pooling, and determines whether material is worth carrying forward at all.

Independent verification is evidential. A sample from the finished lot is submitted to an unaffiliated laboratory, which reports purity and identity without knowledge of the expected result being used to shape it. The published certificate reflects that report.

Test layers and the attributes each establishes
Layer	Typical methods	Attribute established
In-process	Analytical HPLC of fractions	Whether purification is converging
In-house release	RP-HPLC, UV detection	Chromatographic purity of the pooled lot
Independent	HPLC and mass spectrometry	Purity and sequence identity, reported externally
Supporting	Water content, residual solvent screens	Physical characteristics of the lyophilized cake

Test layers and the attributes each establishes

Sampling matters as much as the assay

A result is only meaningful if the sample represents the lot. Samples are drawn after the material is homogenised and before or during the fill run, and the sampling point is recorded so a later question can be answered precisely.

Where a lot is filled across multiple runs, the sampling plan reflects that. A single sample from the beginning of a long fill is not treated as representative of the whole.

Publication of results

Results are published against the lot number rather than the product in general. When a new lot supersedes an older one, both remain accessible so that a laboratory holding older material can still read the document that applies to it.

Frequently asked questions

Why test twice?

In-house testing is fast and guides production decisions. Independent testing provides evidence that does not depend on the producer's own instruments or interpretation. The two answer different questions.

Are older lot certificates removed when a new lot is released?

No. Superseded certificates stay available so material already in a laboratory's freezer can still be matched to its own analytical record.

Related research compounds

Compounds with a published certificate of analysis, where the methodology described on this page can be read against a real lot record.

References and standards

ICH Q2(R2) Validation of Analytical ProceduresInternational Council for Harmonisation
USP <1225> Validation of Compendial ProceduresUnited States Pharmacopeia

Editorial attribution

PrimeGen Co. laboratory documentation team

Editorial and analytical documentation

Our documentation team maintains lot records, certificate presentation and the educational material on this site. Pages describe our own internal practices and published analytical methodology; they are not an independent certification of any kind.