Discussion
The use of additives and the wide dynamic range of the ECL platform resulted in an accurate and consistent ECL immunoassay that was able to specifically detect sTnI (Tnni2) in rat serum. This method can be applied to safety assessment in early drug development.
Methods
Due to the nature of the troponin subunits to form intermolecular complexes and to oxidize under various environmental conditions, the optimal assay required the use of a combination of chelating and reducing agents in the sample preparation. It also required the selection of capture and detection antibodies with specificity to the reduced sTnI monomeric subunit and includes a capture antibody specific for sTnI Type 2 (Tnni2), which is associated with Type 2 "fast twitch" muscle fibers.
Results
We have developed a sensitive and specific assay to detect the concentration of rat sTnI in serum using an electrochemiluminescent (ECL) immunoassay platform with a sensitivity of 2.4 ng/ml and with minimal cross-reactivity with rat cardiac TnI (Tnni3).