HTS / HCS Screening Translocation assays
DRAQ5™ is the ideal live or fixed cell DNA dye for GPCR & all translocation assays
NEW: DRAQ7™ is the choice if you only work with fixed cells
DRAQ5™ is used successfully in HTS / HCS by most of the largest Pharma companies and high volume screening centres across the world.
Many of the translocation / redistribution / GPCR assays use GFP as a signal for the response of the target protein to a compound from the candidate library. Automated imagers require labelling of a nucleus from which to localise the signal in the assay.
Previously, this has been done with UV dyes like Hoechst 33342. Problematically, Hoechst 33342 emission overlaps with GFP meaning two plate scans to acquire each well image.
DRAQ5™ advantages
- DRAQ5™ emits in the far-red (665 nm and beyond), making it ideal for use with GFP and all visible range-fluor tagged ligands. Due to this spectral separation the GFP and nuclear signals can be captured simultaneously. For this reason alone, the screening time is HALVED!!
- DRAQ5™ differentially stains both the nucleus and cytoplasm making it ideal for any translocation (or Redistribution™ / Transfluor™) assay.
- Hoechst dyes are actively pumped out of MDR cells - so you will not see these cells in your screen. DRAQ5™ is NOT pumped out of MDR+ cells, so importantly you see ALL the cells in the well, including the MDR cells.
- 10-15% of the library you are screening may be naturally UV fluorescent, causing "white out" in the wells if you use a DNA dye like Hoechst. Since DRAQ5™ is excited in the visible range (633 nm / 647 nm) this is avoided - making the compound screen 10-15% more efficient and reducing complexity and cost of imaging hardware.
USEFUL LINKS:
A selection of publications where DRAQ5 has been described for high content screening:
- In GE Healthcare Biosciences' IN Cell™ AKT1-GFP Assay protocol DRAQ5™ halves the assay scan time for a few cents per well, surely a very small price for such an improvement. Link to the user manual which describes the advantage of DRAQ5™'s emission not overlapping with that of GFP cf. Hoechst dye.
- Email: enquiry@biostatus.com
- Telephone: +44 1509 558163
- Fax: +44 1509 651061