has endpoint uses detection instrument has assay supporting method has assay supporting method physical detection method mass spectrometry This method is used to detect compounds that are bound to the protein targets. The unbound compounds are separated by affinity based, size exclusion, or ultrafiltration methods. The bound compounds are eluted from the protein and detected by mass spectrometry. Based on the separation method, the throughput varies: between 200-2700 compounds can be loaded in each run for separation. Mass spectrometry is used to determine the chemical structure of molecules. The samples are vaporized, followed by ionization and then the mass to charge ratio of the particles is analyzed. MS protein preparation method protein level epigenetic profile Velos-MS