Glutathione is a tripeptide with one unusual bond that lets it survive inside the cell. The gamma linkage, the GSH/GSSG couple, and why the ratio is the only number that matters.
Peptides degrade through a small number of specific reactions — deamidation, oxidation, hydrolysis, disulfide scrambling, aggregation and adsorption. How to tell which apply to your sequence.
GHK-Cu is a coordination complex, not a peptide with copper added. What that means for buffers, chelators, pH, the blue colour as a sanity check, and how to read the literature.
Solvent selection, a step-by-step procedure, concentration calculations and realistic storage expectations for lyophilized research peptides.