Quality testing

Every lot of Dr Jays Peptides ships with an independent Certificate of Analysis. The four analyses below define what's actually in the vial.

HPLC purity (≥99%)

Reverse-phase high-performance liquid chromatography separates the target peptide from synthesis byproducts. Purity is reported as the integrated area of the main peak over the total chromatogram.

Mass spectrometry (identity)

ESI- or MALDI-TOF mass spec confirms the molecular weight matches the theoretical mass of the intended sequence, ruling out deletion or addition products at the synthesis stage.

Peptide content

Net peptide content (vs. counter-ion and water mass) is determined by amino-acid analysis or UV quantification. It's how much of the labeled mass is actually active peptide.

Endotoxin

LAL (Limulus amebocyte lysate) testing quantifies bacterial endotoxin contamination. Research-grade lots target < 0.5 EU/mg.