PROTAC Screening: Alternative Methods to Increase Throughput

Immunoblotting is the current gold standard method for screening Proteolysis-Targeting Chimeras (PROTACs) in drug discovery. Immunoblotting is an effective semi-quantifiable method for assessing the presence/absence of a target protein. Next-generation methods, including the Simple Western™ WES and JESS, use a capillary-based immunoblotting and offer significant improvement by enabling reliable quantification when compared to conventional Western Blotting. This makes next-generation methods the better choice for PROTAC screening.

However, Simple-Western™ immunoblotting are limited by throughput and is generally unable to generate dose-response analysis of new PROTACs without significant labour and time. In addition, for next generation methods, the cost of consumables can be prohibitive. For these reasons, alternative methods for PROTAC screening were developed.

The methods shown, can utilise a 96-well format, with potential to scale-up to 384-well format, and screen multiple PROTACs in parallel as a first pass screen for hit identification. They can increase the throughput for PROTAC screening while limiting costs. This study compares the methods with Jess-based methods for PROTAC screening and hit identification.