Cyclic GMP, [¹²⁵I]-RIA Kit, 200 Assay tubes

This kit is designed for assaying cyclic GMP using radioimmunoassay methodology. The basic principle of radioimmunoassay is the competition between radioactive and non-radioactive antigen for a fixed number of antibody binding sites. If increasing amounts of non-radioactive antigen (e.g., standards or unknowns) and a fixed amount of radioactive antigen are allowed to react with a constant amount of antibody, a decreasing amount of radioactive antigen is bound to the antibody. This relationship can be expressed as a standard curve and the amount of unlabeled antigen in a sample determined by interpolation from this curve.

The PerkinElmer Life Sciences radioimmunoassay kit for the determination of cyclic GMP is adapted from the procedures of Steiner, et al.¹. The labeled antigen is a succinyl tyrosine-[¹²⁵I]-methyl ester derivative of cyclic GMP. Separation of bound from free antigen is achieved by the use of a pre-reacted primary and secondary antibody complex. The primary antibody was prepared in rabbits against a succinyl cyclic GMP-albumin conjugate, while the second antibody was prepared in sheep against rabbit globulin.

1. Steiner, A. L., Parker, C. W. and Kipnis, D. M., J. Biol. Chem. 247:1106 (1972).