Affinity Selection Mass Spectrometry

Affinity selection mass spectrometry (ASMS) offers a variety of advantages compared to DEL screening. ASMS eliminates the need for labels, tags, or other modifications on both test compounds and targets, meaning that binding occurs in a native context. ASMS can readily screen protein complexes and other challenging targets, and compound libraries are comprised of Rule-of-Five-compliant drug-like molecules. All hits are available for immediate validation and follow-up, while DEL hits must be resynthesized and purified for orthogonal confirmation. ASMS is quantitative (peak areas are proportional to target occupancy), enabling hit triage and determination of relative selectivity.

We have extensive experience using our ASMS screening services to study hundreds of targets tested against tens of millions of compounds. We can screen our in-house library of 400K compounds, as well as third-party libraries, and internal client libraries. While we typically screen Rule of Five compliant chemical libraries, we can also screen macrocycles. We offer target QC on proteins and RNA to ensure accurate screens.

We recommend clients run a secondary screen to confirm hits in small pools of one to five compounds. We can also rank order hits by competitive binding, give quantitative information on target occupancy, and determine binding affinity for Structure-Activity Relationship (SAR) studies.