Rapid heterologous haptene radioimmunoassay for insect moulting hormone

Several recent studies suggest that moultin hormone (MH) is involved in regulating both moulting and ecdysis in insects. Radioimmunoassay proved to be the most suitable technique for the examination of the physiological MH levels of insects. The specificity of the RIA technique, coupled with TLC, provides perhaps the most elegant means for determining the presence of molecules of a specific structure. All moulting hormone RIA methods described to date are homologous RIA systems, i.e., they utilize the same steroid as antigen and as tracer. The system described here uses polypodine B for the immunization and ecdysone as the tracer and is thus a heterologous system. The antigen used is the conjugate of RSA and the 6-oxime derivative of the steroid, the side chain acting as antigenic determinant. The conditions of assay are such that the time of assay is 50 min as compared to previous systems which generally required a day