Figure 1.

Schematic diagram of the acid extraction process. Sperm or eggs are harvested from L. pictus or cells are prepared from mouse pancreas. Agonist is incubated with the cell preparation, then HClO₄ is added to stop the reaction at the required time point. The sample is then sonicated to disrupt the cells and centrifuged to pellet the protein for subsequent assay. The supernatant is neutralised with an equal volume of 2 M KHCO₃, or other bases where indicated, in preparation for analysis using the radioreceptor binding assay.