A micro-radioimmunoassay for the measurement of intracellular cAMP

We have developed a rapid and sensitive micro-radioimmunoassay for the detection of cellular cAMP. The assay employs a simple method for preparing cellular lysates that requires as few as 500 cells per data point. Cellular lysates are incubated with cAMP-specific antibody complexes and [125I]cAMP in 96-well plates, harvested onto glass fiber filters and analyzed using a commercial autoradiograph imaging system. This method provides significant savings in reagents and may be particularly useful in situations where only a limited number of cells are available.