Progressing only compounds showing activity in either ADP-Glo TM or SPA formats and excluding those with counter-screen (CS) activity left 171 (36%) compounds for further consideration. 7 compounds showing binding to DNA (SYBR TM Gold intercalating assay) were excluded from further consideration. The remaining 164 (96%) compounds were then profiled in a high-enzyme assay (7-fold increased enzyme compared to screening. IC50 shifts under this mode are also indicative of artefactual inhibition), a SPA interference assay, high substrate assay, and against MutSα. A selection of 44 (27%) compounds was then made using three distinct approaches: 1) A holistic scoring function based on the profiling assay data; 2) Application of a cut-off at 3-fold IC50 shift in the high enzyme assay; 3) Selection of the most potent remaining compounds in the SPA assay. These compounds were progressed into a centrifugation assay to remove any remaining potential aggregating artifacts, resulting in 25 (57%) compounds for either repurchase and HPLC purification or resynthesis. Retesting of these fresh batches of material ultimately led to 11 (44%) compounds of interest (Figure ).