HTRF ® cyclic AMP assay : new optimized cell-based assay for a better investigation of Gi coupled receptors

The cAMP measurements on CHO-K1 cells that stably expressed the CCR1 receptor were performed by using the two different HTRF® cAMP assays - femtomolar and dynamic. The principle of these cAMP assays is based on a competition between cAMP produced by cells and cAMP-XL665 conjugate for the binding with monoclonal anti-cAMP-cryptate conjugate (cf. figure below). Both assays are run with the new protocol consisting of only four dispensing steps where an equal volume of each assay component is added successively as described in the figure alongside. The HTRF ® conjugates are prepared in lysis buffer so that the cell lysis and the detection step can be performed simultaneously. Both assays are suitable for suspended or adherent cells. The cAMP assays performances calculated from the standard curves are listed in the table 1.