Two desired epitopes of cTnI benefit for preparation of standardized monoclonal antibodies

Acute myocardial infarction (AMI) is one of the most severe cardiovascular diseases in humans, often resulting in unexpected death. Early detection is critical for patient survival. Sandwich ELISA is a common method for the detection of AMI. However, ELISA kits from different manufacturers can give different results, in part because of the lack of standardized epitopes. Therefore, the purpose of this study was to find two standardized epitopes. We predicted two antigen epitopes and respectively immunize mice to manufacture standardized monoclonal antibodies. Eight monoclonal antibodies were prepared. Monoclonal antibodies 7D2 and 2C3 were selected with high affinity, and their characteristics were explored. The results show that monoclonal antibodies 7D2 and 2C3 can both bind to various modified forms and complexes of cardiac troponin I (cTnI), were not cross-reaction with related antigens of normal human serum and can be paired. Therefore, we deem epitopes 30 to 42 and 77 to 89 standardized epitopes.