The cAMP assay is a competitive ELISA that permits cAMP measurements within the standard curve range of 0.078-10 pmol/ml, sensitivity (80% B/B0) of 0.1 pmol/ml for acetylated cAMP. Non-acetylated cAMP has a range from 0.3-750 pmol/ml and a sensitivity(80%B/B0) of approximately 3 pmol/ml.