A lyophilized peptide keeps best sealed, dry, dark and cold. Water and heat drive most of the chemistry that degrades a peptide, and freeze drying has already removed most of the water. That changes what matters on arrival. A sealed dry vial handles a short warm spell far better than it handles water, and the […]
A certificate of analysis answers four questions in a fixed order: which batch was tested, whether it is the right molecule, how much of the detected material is that molecule, and who stands behind the result. Read it as evidence about one batch, not a description of a product. Every line either ties back to […]
A 99% purity figure on a peptide certificate is the main peak’s share of UV peak area in one chromatogram, recorded at one wavelength on one column under one gradient. It is not the share of the vial’s weight that is peptide. The number describes what the detector saw and separated. Water, counterions, salts and […]