High sensitivity of new generations of cTnI assays helps to register even minor events in myocardial tissue. However, presence of cTnI-specific autoantibodies in blood of some patients makes detection of the antigen almost impossible. Effect of autoantibodies becomes more prominent in the cases of minor events, when antigen concentration in human blood is low. Our specialists have distinguished major epitopes recognized by autoantibodies and thus we have been able to select antibodies that could be used for the development of cTnI assays that are not affected by autoantibodies in the sample. It is also necessary to remember that highly sensitive troponin I assay should utilize antibodies specific to the epitopes that are not affected by modifications (free and complexed, phosphorylated, partially digested by proteases and others) of the antigen that could occur in human blood. HyTest offers hsTnI™ monoclonal antibodies which can be used when developing such an assay.