Lab Quality & Testing
Method Validation Basics: ICH Q2 for Peptide Assays
Accuracy, precision, specificity, linearity, range and robustness — the validation characteristics that separate a number from a trustworthy number.
Published October 4, 2026 · 7 min read
By Novanta Research Editorial Team
Evidence scope: Analytical and compendial guidance only. Method validation describes measurement quality and does not establish clinical safety or fitness for human use.
What validation establishes
An analytical procedure is only as useful as the evidence that it measures what it claims to measure. ICH Q2(R2), revised in 2023, defines the validation characteristics that demonstrate this: specificity, accuracy, precision, linearity, range, detection and quantitation limits, and robustness.
A purity figure from an unvalidated method is a number without context. The same instrument, run without demonstrated specificity, can overstate purity by co-eluting an impurity under the main peak.
Sources for this section
- Validation of Analytical Procedures Q2(R2) — International Council for Harmonisation, 2023
The characteristics that matter for peptide purity
Specificity asks whether the method separates the target peptide from its likely impurities — deletion sequences, oxidation products, deamidated forms. Accuracy and precision ask whether the result is right and repeatable. Linearity and range define the concentrations over which the answer holds.
For peptide-related impurities, the literature describes these as distinct analytical challenges rather than a single problem, which is why orthogonal methods remain standard practice.
Sources for this section
- Related impurities in peptide medicines — Journal of Pharmaceutical and Biomedical Analysis, 2014
What to look for as a buyer
A certificate rarely reproduces a full validation report, but it should state the method, the column and conditions or a reference to them, the detection wavelength, and the integration and reporting thresholds. Absent those, the percentage cannot be interrogated.
Questions worth asking any supplier: was the method shown to resolve the known impurity profile of this sequence, and what reporting threshold applies to the stated purity?
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For laboratory and research use only. Not for human or veterinary consumption. Novanta Research is not a compounding pharmacy and nothing in this article is medical advice or a claim that any compound diagnoses, treats, cures or prevents any condition.