A radioimmunoassay for human serum myoglobin: method development and normal values.

We describe a radioimmunoassay that will measure both normal and above-normal concentrations of myoglobin in serum. Myoglobin isolated from human pectoralis muscle was purified by (NH4)2SO4 fractionation and Sephadex gel filtration and injected into rabbits to elicit antisera. Myoglobin was radiolabeled by an acylation with [125]-3-(4-hydroxyphenyl) propionic acid N-hydroxysuccinimide ester. With the purified myoglobin and antisera, we then developed a radioimmunoassy that involves simultaneous regent addition, a 3.5-h incubation at 37 degrees C, and separation of the antibody-bound fraction by precipitation with polyethylene glycol. Information is given on detection limit, precision, linearity, recovery, and specimen preservation. Cross-reactivity to human hemoglobin is negligible. Finally, we investigated the possible relationship between serum myoglobin concentration and muscle mass.