Horseradish peroxidase-intrinsic factor conjugates

摘要

This invention preferably presents a non-isotopic competitive assay for Vitamin B12 (B12), utilizing intrinsic factor (IF) labelled with horse radish peroxidase (HRP). HRP and IF are by coupled via heterobifunctional cross-linking agents, Succinimidyl-4-(p-maleimidophenyl)butyrate (SMPB) and N-Succinylimidyl-5-acetylthioacetate. In addition, a method for stabilizing the resultant conjugates by pretreatment with N-ethylmaleimide is disclosed.