DNA Replication Inhibitors Screening

The chemicals used were 100 mM stock solution of BrdU (Merck, B5002) and 10 mM stock solutions of PARG inhibitor (PDD0017273, Tocris, 5952; Merck, SML1781), PARP inhibitors (KU0058948, Axon Medchem, Axon 2001; Olaparib, ApexBio, A4154), FEN1 inhibitor (UOS-33991; compound 17 in ref. ^{52 (link)} and synthesized in-house as described in ref. ^{11 (link)}), REV1 TLS inhibitor (JH-RE-06, Axon Medchem, Axon 3002) and EdU (Cambridge Bioscience, CAY20518) were prepared in dimethyl sulfoxide (DMSO). CldU (Merck, C6891) and IdU (Merck, I7125) were dissolved directly in culture medium at a final concentration of 2.5 mM, and thymidine (Merck, T1895) in culture medium at 200 mM. 1 mCi per ml ³H-Thymidine (PerkinElmer, NET027W005MC) in 2% ethanol and 99% MMS were added directly to culture medium to a final concentration of 2 µCi per ml and 0.01%, respectively.