cAMP-Screen® and cAMP-Screen Direct® Chemiluminescent Immunoassay Systems

Cellular Cyclic AMP Quantitation

Flexible Applications

The cAMP-Screen® and cAMP-Screen Direct® assays are used with established cell lines for functional measurements of endogenous receptors (Figure 1), with cell lines expressing exogenous ligand receptors, and with primary cell cultures to investigate their response to treatment with the appropriate ligands. The cAMP-Screen® assay has also been used for cAMP quantitation from tissues. In addition, the assays can be used for high-throughput screening assays for compounds which stimulate or inhibit cAMP production via interference with receptor function or signal transduction pathways. 

The cAMP-Screen® and cAMP-Screen Direct® assay systems have been used with a wide range of cell lines containing endogenous receptors, including epithelial, neuronal, endocrine, pancreatic, and tumor-derived cell lines, as well as stably- and transiently-transfected CHO and HEK cells exogenously expressing many different GPCRs, neurotransmitter, adenosine, and hormone receptors. Primary cell types include epithelial, neuronal, adipose, osteoblast, and dendritic cells as well as platelets, hepatocytes, myoblasts, fibroblasts, and T cells. Mouse and Drosophila brain tissues have also been used with these assay systems.

Rapid and Simple Detection Method

The cAMP-Screen® and cAMP-Screen Direct® competitive immunoassay systems are formatted for maximum flexibility to permit either manual assay or automated high-throughput screening with 96- or 384-well microplates. The system utilizes CSPD® substrate, a high-sensitivity chemiluminescent alkaline phosphatase (AP) substrate with Sapphire-II™ luminescence enhancer. This ready-to-use substrate/enhancer reagent generates a light signal that is measured 30 minutes after addition, with glow emission lasting several hours. 

With the cAMP-Screen Direct® system, cells are grown and lysed directly in the assay plate. For cells requiring specialized growth surfaces, we recommend using the cAMP-Screen® system after culturing cells in appropriate surface-modified culture plates (Figure 2). Lysates are incubated with a cAMP-AP conjugate and an anti-cAMP antibody in the secondary antibody–coated assay plate; the resulting immune complexes are captured in the plate. The captured immune complexes are washed to remove unbound cAMP-AP, chemiluminescent substrate/enhancer is added, and the resulting signal is measured in a luminometer. A low level of cAMP yields minimal competition with the cAMP-AP conjugate for binding to anti-cAMP antibody, resulting in a high chemiluminescence signal (Figure 3). Increased levels of cAMP compete with and thus reduce the amount of cAMP-AP conjugate in the captured immune complexes. Standard curves display an inverse correlation between signal intensity and free cAMP concentration and allow quantitation of the amount of cAMP.

High Sensitivity and Wide Dynamic Range

The cAMP-Screen® and cAMP-Screen Direct® systems enable ultrasensitive determination of cAMP levels in cell lysates: less than 0.2 pmol/well cAMP in the 384-well format. The dynamic range covers from less than 0.06 to greater than 6000 pmol/well cAMP in the 96-well format, and from less than 0.2 to greater than 200 pmol/well cAMP in the 384-well format, without sample dilution or modification. In addition, the assay exhibits very low cross-reactivity with other adenosine-containing or cyclic nucleotides (Table 1).

Take Advantage of Maximum Flexibility

The cAMP-Screen® and cAMP-Screen Direct® Chemiluminescent Immunoassay Systems enable rapid and convenient quantitation of cellular cAMP. Formatted for maximum flexibility, the cAMP-Screen assays are available in either 96-well or 384-well formats, and in sizes that are ideal for evaluation, research and development, or primary and secondary screening. Learn More About cAMP-Screen® and cAMP-Screen Direct® Chemiluminescent Immunoassay Systems.

PLEASE NOTE: These products will not be available through Invitrogen website until November 7th in 2011. Please visit the Applied Biosystems web site for ordering information.

For Research Use Only. Not intended for any animal or human therapeutic or diagnostic use.