Stability of cardiac troponins and CK-MB mass isoenzyme

The stability of an analyte can have an important influence on its diagnostic performance and therefore should be documented before an analyte is introduced into routine practice. The stability of creatine kinase MB isoenzyme (CK-MB), troponin I and troponin T was studied by incubating samples at temperatures between 26 degrees C and 39 degrees C for periods up to 5400 min. Arrhenius plots were made which showed that all three proteins demonstrated a rapid decrease in stability between 15 degrees C and 20 degrees C. The activation energies for CK-MB, troponin I and troponin T were 7.7, 6.34 and 6.34 cal/mol, respectively.