Abstract: An immunochemical process and test kit for determining accurately the amount of creatine kinase-MB isoenzyme (CK-MB) in biological fluids employing two separate immunoassays to a single sample of the biological fluid. This process and test kit are useful in diagnosing myocardial infarct.

Abstract: An immunochemical process and compositions for determining rapidly and accurately the amount of creatine kinase-MB isoenzyme (CK-MB) in biological fluids. The process employs a triple antibody technique which leads to the formation of an immuno-complex having a measurable label. This process and the resulting complex are useful in determining whether a patient has suffered a myocardial infarct.

Abstract: LDH.sub.1 levels in serum samples can be rapidly and accurately assayed by a novel immunochemical technique. In such procedure the serum sample is treated with soluble antibodies against the M subunit and the resulting antigen-antibody reaction product is insolubilized with a second antibody supported on an insoluble material. The resulting supernatant containing only LDH, isoenzyme is assayed for enzymatic activity by conventional procedures. The assay of LDH.sub.1 levels in sera is useful in determining whether the subject has undergone a myocardial infarction.

Abstract: An improved method for immunoassay for antibodies to microbial organisms is disclosed. The improvement involves the use of diluted anti-human IgG to produce a non-visible agglutinate of the microbial antigen-serum antibody cojugate. Such method provides for maximum label binding and thus maximum assay sensitivity compared to the previously employed conjugate precipitation method. The present improvement is particularly useful in a radioimmunoassay for detecting antibodies to Neisseria gonorrhoeae (N.g.) or rubella virus in sera.