Evotec Streamlines Testing of Quarter Million Compounds with Promega HaloTag® Technology

Evotec recently completed its largest screening project with the use of Promega HaloTag® technology. Evotec reported screening over 250,000 unique compounds on live cells with an assay designed to detect the internalization of a novel membrane receptor. The results identified compounds that have potential to be first in class for the therapeutic area.

After extensive testing, Evotec reported that HaloTag delivered the strongest performance compared to other technologies. In contrast to other fluorescent proteins, the proteins fused with HaloTag do not fluoresce until the HaloTag binds a fluorescent ligand. HaloTag allowed Evotec scientists to specifically label receptors with low background levels and increased sensitivity compared to other technologies.

The screen was conducted with a throughput of over 10,000 compounds per day on a confocal plate imager, using a stably transfected cell line. After labeling the surface pool of receptors, compounds were screened for their ability to inhibit receptor internalization.

"We are pleased to be able to provide our customers with such rich information, so quickly," says Mark Slack, Senior Scientist at Evotec. "It is advanced technologies like HaloTag that continue to expand our capabilities and service to our pharmaceutical and biotech partners."

Cell surface receptors are frequently targeted for new drug compounds, and their localization in the cell often governs their cellular activity. Promega has specifically developed ligands for HaloTag of differing colors; some that do not enter the cell on their own along with ligands that do passively enter the cell. Using these tools, scientists can label different pools of HaloTag proteins- those inside and those on the cell surface.