I-C-Peptide (i-C-Peptide) iyi-peptide exhumanisayo eyakhiwe ama-amino acid angu-31 enesisindo sama-molecule esingama-Dalton angu-3021. Ama-β-cell e-pancreatic e-pancreas akhiqiza i-proinsulin, okuyi-chain yeprotheni ende kakhulu. I-Proinsulin ihlukaniswa ibe yizigaba ezintathu ngaphansi kwesenzo sama-enzyme, futhi izingxenye zangaphambili nangemuva ziphinde zixhunywe kabusha ukuze zibe yi-insulin, eyakhiwe uchungechunge lwe-A ne-B, kuyilapho ingxenye ephakathi izimele futhi yaziwa ngokuthi i-C-peptide. I-insulin ne-C-peptide zikhishwa ngamanani alinganayo, futhi ngemva kokungena egazini, iningi le-insulin liyavalwa yisibindi, kuyilapho i-C-peptide ingatholakali kakhulu yisibindi, kanye nokuwohloka kwe-C-peptide kuhamba kancane kune-insulin, ngakho-ke ukuhlushwa kwe-C-peptide egazini kuphakeme kunokwe-insulin, ngokuvamile izikhathi ezingaphezu kwezi-5, ngakho-ke i-C-peptide ibonisa ngokunembile umsebenzi wama-β-cell e-pancreatic islet. Ukulinganiswa kwezinga le-C-peptide kungasetshenziswa ekuhlukaniseni isifo sikashukela kanye nokuqonda umsebenzi wamaseli e-pancreatic β ezigulini ezinesifo sikashukela. Ukulinganiswa kwezinga le-C-peptide kungasetshenziswa ekuhlukaniseni isifo sikashukela nokuqonda umsebenzi wamaseli e-pancreatic β ezigulini ezinesifo sikashukela. Njengamanje, izindlela zokulinganisa i-C-peptide ezisetshenziswa kakhulu emitholampilo yezokwelapha zifaka phakathi i-radioimmunoassay, i-enzyme immunoassay, i-electrochemiluminescence, ne-chemiluminescence.