Testing methodology.
The analytical and microbiological methods that support lot-specific certificates of analysis.
Scope
Cendrix research materials are characterized on a per-lot basis using a combination of chromatographic, mass-spectrometric, and microbiological methods. The exact panel applied to a given lot depends on the molecular class, the matrix, and the intended use as a research material. Method selection follows applicable compendial chapters and recognized peptide-characterization practice.
Identity
Molecular identity is supported by mass spectrometry, commonly LC-MS or MALDI-TOF, comparing the observed monoisotopic or average mass against the theoretical mass for the labeled sequence and modifications. Identity is reported with the method used and the observed mass.
Purity
Relative purity is assessed by reversed-phase HPLC under documented conditions. The reported value is the chromatographic area percent of the principal peak at the specified detection wavelength. Purity is reported alongside, not in place of, identity and content.
Content
Peptide content, distinct from purity, is determined by orthogonal methods that quantify the actual peptide mass present. Methods may include nitrogen determination, amino acid analysis after hydrolysis, or quantitative NMR, selected based on the molecule and matrix.
Counterion, water, and residual solvents
Where applicable, counterion content, water (loss on drying or Karl Fischer titration), and residual solvents (gas chromatography) are reported. These contribute to total vial mass and explain the gap between chromatographic purity and peptide content.
Microbiological controls
Bioburden, sterility, and bacterial endotoxin testing (LAL or recombinant Factor C) are applied where appropriate to the matrix and intended research handling. Results are method-specific and reflect the test conditions documented on the certificate.
Limits of testing
Analytical results characterize the lot tested under the methods specified. They do not constitute safety claims, do not certify suitability for human use, and do not guarantee performance in any specific experimental system. Researchers are responsible for verifying that the documented methods and limits meet the requirements of their own protocols.