A modification of a protein-binding method for rapid quantification of cAMP in cell-culture supernatants and body fluid

Anal Biochem. 1990 Sep;189(2):231-4. doi: 10.1016/0003-2697(90)90113-n.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Glands / enzymology
  • Animals
  • Body Fluids / chemistry*
  • Cattle
  • Cells, Cultured
  • Culture Media
  • Cyclic AMP / analysis*
  • Cyclic AMP / urine
  • Humans
  • Male
  • Protein Binding
  • Protein Kinases / metabolism
  • Radioimmunoassay
  • Reference Standards
  • Tritium


  • Culture Media
  • Tritium
  • Cyclic AMP
  • Protein Kinases