A recent publication in PLoS ONE has again proved DRAQ5 to be the perfect choice as nuclear counterstain in HCS assays. Rosado et al (from the lab. of Dr Wolfgang Link at Centro
Nacional de Investigaciones Oncologicas, Madrid) described development of an exciting new technology that permits the monitoring of compounds interfering with pathways in tumour
cells. This work demonstrated DRAQ5 as the ideal nuclear counterstain - it efficiently labels live cells, stably demarks the nucleus and has no spectral emission overlap with either CFP or YFP. Furthermore, it demonstrated the  compatibility of DRAQ5 with the Pathway 855.