The GeneBLAzer® CHO.K1-D1 cell line from Invitrogen stably expresses both the beta-lactamase gene downstream of the cAMP response element (CRE) and the dopamine D1 receptor. Stimulation of the cells with dopamine D1 receptor agonists results in transcriptional activation of the beta-lactamase gene through CRE. A FRET-enabled substrate (CCF4-AM) fluoresces green in the absence of beta-lactamase reporter activity, and blue when cleaved.

The reporting of ratiometric fluorescence data on a per cell basis dramatically reduces cell requirements from those used in bulk fluorescence assays, without compromising assay performance.  Acumen microplate cytometers are capable of rapid analysis of the entire well area of all wells on the microplate. Screening the whole well also has the advantage of avoiding false positives caused by inconsistencies in cell distribution in the well.

We have used the Acumen ^eX3, equipped with a 405 nm laser, to analyse D1 receptor activation in the GeneBLAzer CHO.K1-D1 cell line. 

This partnership enables an efficient method of detection and analysis of cell lines expressing the beta-lactamase reporter gene system with throughputs of 10 minutes for any type of microplate.