Mirin

Colcemid (L-6221, Biochrom AG) was used at 0.1 μg/ml to accumulate cells at metaphase (Stock: 10 μg/ml in phosphate-buffered saline (PBS) w/o Ca⁺⁺, Mg⁺⁺). Calyculin A (C-3987, LC laboratories) was used at a concentration of 50–100 nM (Stock: 10 μM in DMSO; dimethyl sulfoxide) for induction of premature chromosome condensation (PCC) during the G2-phase of the cell cycle. Carnoy's fixative was prepared by mixing 3 parts methanol (Sigma Aldrich) and 1 part glacial acetic acid (Carl Roth GmbH & Co.) just before use. A total of 2.5 ml of ready-to-use Giemsa stain (Carl Roth GmbH & Co.) was diluted in 50 ml of Sorenson's buffer (10582–013, Gibco, Invitrogen) to stain metaphase chromosomes, or PCCs. Entellan (Merck) was used as mounting medium.
The Parp-1 inhibitor PJ34 (Calbiochem) was used at 5 μM final concentration. 8-(4-Dibenzothienyl)-2-(4-morpholinyl)-4H-1-benzopyran-4-one (NU7441, Tocris), a DNA-PKcs inhibitor, was dissolved in DMSO at 10 mM and was used at 5 μM final concentration. L82 (Lig1 inhibitor) and L67 (Lig1 and Lig3 inhibitor) (36 (link)) were purchased from Specs (The Netherlands) and used at 100 μM final concentration. Mirin (sc-203144, Santa Cruz Biotechnology Inc., Chemistry Department of Indianapolis University) was used at 300 and 500 μM for translocation and DSB end resection assays, respectively.