title: A modification of a protein-binding method for rapid quantification of cAMP in cell-culture supernatants and body fluid.
abstract: A modification of a protein-binding method (B. L. Brown et al., 1971, Biochem. J. 121, 561, 562) for measurement of adenosine 3',5'-cyclic monophosphate (cAMP) in cell-culture supernatants and urine is described. With filtration over glass-fiber filters and a semiautomatic cell harvester instead of charcoal precipitation as in the original method, free [3H]cAMP tracer was rapidly and uniformly separated from that which was protein-bound. Sensitivity was increased with a high ionic strength buffer and a tritiated cAMP tracer with high specific activity. There was good agreement between cAMP values obtained with the protein-binding method and commercially available radioimmunoassays that were used as reference methods. cAMP could be determined accurately over the range 0.15-8.0 pmol/sample. More than 500 samples could be assayed in duplicate or triplicate in less than 6 h.
authors.affiliation: Department of Pharmacology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Nordstedt
authors.forename: B B
authors.initials: BB
authors.lastname: Fredholm
mesh_terms: D000311:Adrenal Glands / Q000201:enzymology; D000818:Animals; D001826:Body Fluids / Q000737:chemistry*; D002417:Cattle; D002478:Cells, Cultured; D003470:Culture Media; D000242:Cyclic AMP / Q000032:analysis* / Q000652:urine; D006801:Humans; D008297:Male; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D011863:Radioimmunoassay; D012015:Reference Standards; D014316:Tritium
chemical_list: D003470:Culture Media; D014316:Tritium; D000242:Cyclic AMP; D011494:Protein Kinases