Optimization of the immunoradiometric assay (IRMA) for the quantification of c-peptide in rat serum for research applications

C-peptide concentration in blood is independent of exogenous insulin administration and its measurement is preferred over insulin because of lack of hepatic extraction and slower metabolic clearance rate. Quantification of C-peptide in rat serum is very important as in the field of diabetic research where rat models are extensively used, especially, in studying the effects of synthesized diabetic drugs. The aim of the present work is to develop rat specific C-peptide immune radiometric assay (IRMA) with adequate sensitivity and range to aid the researchers involved in the drug development. The aim of the present work is to develop an immune radiometric assay (IRMA) with adequate sensitivity and range to aid the researchers involved in the drug development to estimate C-peptide in rat serum. The developed IRMA procedure makes use of a pair of rat C-peptide specific monoclonal antibodies (capture -detector antibody pair) from a commercial source, screened and identified for this purpose along with magnetizable cellulose particles. Detector antibody was radio-labeled with ¹²⁵I by the chloramine-T method and the capture antibody was coupled to a magnetizable cellulose particles by 1, 1'-carbonyldiimidazole (CDI) activation method. The parameters for preparation of each of the IRMA reagents were optimized and evaluated using standard procedures. The stability studies were pursued for each of the reagent separately. Assay procedure will be further evaluated for quality control parameters for the development of a reproducible IRMA procedure which can be employed in the research studies such as diabetes, hypoglycemia and insulinoma using rat models, research studies such as on diabetes, hypoglycemia and insulinoma using rat models