An improved assay for cyclic GMP using an insect binding protein.

Protein from silkmoth pupal fat body was used to develop a simple radioisotope-competition binding assay for cGMP, with increased sensitivity and specificity over the currently used protein binding assay (2). With this assay, we have initiated a study of the distribution of cGMP in crickets, which contain unusually high levels, as previously reported by Ishikawa et al. (11).