Specific for human proinsulin (different epitopes), Kd 2.6 x 10-7 M. Not cross-reacts with human, bovine and porcine insulin, bovine and porcine proinsulin, and human C-peptide. Can be used for detection of human proinsulin in two-site enzyme immunoassay, recommended pairs (coating - conjugate): 1G4 - mixture of D6C4 and D3E7 Hytest Cat.# 2IP10; for immunohistochemistry on frozen sections.