Benchmark 3 biorad microtiter spectrophotometer

HeLa, KB2P1.21, and KB2P1.21R1 tumor cell lines were plated in 96‐well plates. HeLa were plated at 2000 cells per well, and KB2P1.21 and KB2P1.21R1 were plated at 1200 cells per well. Cells were first grown for 3 or 24 h and were subsequently treated with the indicated concentrations of olaparib and VE‐821 for 3 days. Methyl‐thiazol tetrazolium (MTT) was added to cells at a concentration of 5 mg·mL⁻¹ for 4 h, after which culture medium was removed and formazan crystals were dissolved in DMSO. Absorbance values were determined using a Bio‐Rad (Hercules, CA, USA) Benchmark III Biorad microtiter spectrophotometer at a wavelength of 520 nm. Viability was determined by comparing absorbance values to those of DMSO‐treated cells. Experiment was performed in triplicate. Graphs show representative experiments, which were performed at least twice.

HeLa, DLD-1, BT-549, HCC1937, KB2P1.21 and KB2P1.21R1 tumour cell lines were plated in 96-wells plates. BT-549 cells were pre-treated with 1 μg ml⁻¹ doxycycline for 48 h. HeLa were plated at 2,000 cells per well, DLD-1 cells at 5,000 cells per well, BT-549 and HCC1937 cells at 1,000 cells per well, and KB2P1.21 and KB2P1.21R1 were plated at 1,200 cells per well. Cells were allowed to attach for 3 or 24 h and were treated with indicated concentrations of olaparib, MK-1775, or MK4827 (all from Axon Medchem, Groningen, the Netherlands) for 3 or 4 days. Methyl-thiazol tetrazolium (MTT) was added to cells at a concentration of 5 mg ml⁻¹ for 4 h, after which culture medium was removed and formazan crystals were dissolved in DMSO. Absorbance values were determined using a Bio‐Rad benchmark III Biorad microtiter spectrophotometer at a wavelength of 520 nm. Proliferation was determined as the relative decrease in signal compared to DMSO-treated cells. Unless mentioned otherwise, statistical significance was tested using Student’s t-test.

RPE-1 cells were plated in 96-wells plates at a concentration of 800 cells per well. After 24 hours, cells were treated with indicated concentrations of olaparib, veliparip, or talazoparib (all from Axon Medchem) for 3 days. Methyl-thiazol tetrazolium (MTT, Sigma) was added to cells at a concentration of 5 mg/mL for 4 hours, after which culture medium was removed and formazan crystals were dissolved in DMSO. Absorbance values were determined using a Bio‐Rad benchmark III Biorad microtiter spectrophotometer at a wavelength of 520 nm.