Troponin-I is a primary biomarker for evaluation of cardiac damage. Recombinant troponin-I is purified at LDI from E. coli. extracts using ion-exchange and troponin-C affinity chromatography. The pure protein can be used as antigen for generation of antibodies. If used for manufacture of immunoassay standards and controls it must be stabilized with skeletal muscle troponin-C (catalog # 3010).