Ko te C-Peptide (C-Peptide) he peptide hono e titoa ana i te 31 ngā waikawa amino me te taumaha ngota o te 3021 Dalton. Ka hangaia e ngā pūtau β o te pancreas te proinsulin, he mekameka pūmua roa rawa. Ka wehea te proinsulin kia toru ngā wāhanga i raro i te mahi a ngā whākōkī, ā, ka honoa anō ngā wāhanga o mua me muri kia huri hei insulin, he mekameka A me te mekameka B, ko te wāhanga waenga he motuhake, ā, e mōhiotia ana ko te C-peptide. Ka tukuna te insulin me te C-peptide i roto i ngā kukū equimolar, ā, i muri i te urunga ki te toto, ka whakakorea te nuinga o te insulin e te ate, ko te C-peptide he onge te tango a te ate, ā, he puhoi ake te pakaru o te C-peptide i te insulin, nō reira he teitei ake te kukū o te C-peptide i roto i te toto i te insulin, neke atu i te 5 ngā wā, nō reira he tika ake te whakaata a te C-peptide i te mahi a ngā pūtau β o te moutere pancreatic. Ka taea te whakamahi i te ine i te taumata o te C-peptide hei whakarōpū i te mate huka me te mārama ki te mahi a ngā pūtau β o te pancreas o ngā tūroro mate huka. Ka taea te whakamahi i te ine taumata C-peptide hei whakarōpū i te mate huka me te mārama ki te mahi a ngā pūtau β o te pancreas i roto i ngā tūroro mate huka. I tēnei wā, ko ngā tikanga ine C-peptide e whakamahia whānuitia ana i roto i ngā whare hauora ko te radioimmunoassay, te enzyme immunoassay, te electrochemiluminescence, me te chemiluminescence.