Magnetic enzyme immunoassay for measuring human IgE.

This paper reports a solid-phase sandwich technique for the assay of human IgE using anti-IgE antibodies bound to magnetic polyacrylamide-agarose beads. Following this technique, IgE to be determined is allowed to bind to the magnetic beads bearing the anti-IgE antibodies. After washing on a magnetic rack, the beads are incubated with enzyme-labeled antibodies, washed again, and then the enzyme activity associated with the beads is measured. The use of magnetic polyacrylamide-agarose beads and of enzyme-labeled antibodies makes the measurement of IgE in human sera easy to perform, safe, and reproducible. This procedure allows the measurement of IgE concentration in serum containing more than 2 IU/ml. The values obtained from 104 human sera closely corresponded to those obtained by radioimmunoassay (correlation coefficient, r = 0.9751).