Sourcing kisspeptin-10 for research

Endocrine and receptor laboratories use kisspeptin-10 as a positive control, for example to confirm that cells transfected with KISS1R give a calcium or inositol phosphate signal. It is normally delivered as a lyophilised powder in sealed vials. Because several closely related kisspeptins exist, and the human and rodent versions differ by one residue, the paperwork deserves a careful look.

Points to verify with the supplier:

• Correct species and length: human kisspeptin-10 is YNWNSFGLRF-NH₂. The rodent decapeptide ends in tyrosine instead of phenylalanine, and kisspeptin-13, -14 and -54 are longer molecules.
• C-terminal amide: the certificate should state the amidated end. A free-acid version is about one mass unit heavier and is not the same compound.
• Mass spectrometry: an observed mass close to 1,302 Da for the specific batch, with the spectrum attached.
• HPLC purity for that batch: a chromatogram with the method stated, not a single figure covering the whole product line.
• Peptide content and counter-ion: the share of the powder that is actually peptide, and whether it is a trifluoroacetate or acetate salt, which can matter in cell assays.
• Consistent records: one batch number on the certificate, vial label and safety data sheet, and a label stating laboratory research use only.

Kisspeptin-10 contains tryptophan, which is sensitive to light and oxidation, so cold, dry and dark storage of the sealed vials helps preserve each lot. Many groups also run a short receptor assay on a new batch before committing it to a long experiment. Online shops, Peptides EU for example, describe these compounds as research materials, and the vial label should say the same.