N dimethylformamide dmf

Telomere PI polyamide TH59 containing a long spacer arm (24 PEG) (Additional file 1: Fig. S1a) was synthesized using the solid-phase synthetic method as described in the references [19 (link), 20 (link), 22 (link)]. ESI–TOF–MS m/z calculated for C₁₅₃H₂₃₂N₄₂O₄₅⁴⁺ [M+4H]⁴⁺ 844.4284 found 844.4276. For chromatin affinity purification, tandem hairpin TH59 was conjugated with desthiobiotin using EZ-Link™ NHS-desthiobiotin (16129, Thermo) to obtain the PI polyamide probe TH59-DB (Fig. 1b and Additional file 1: Fig. S1a) as described in the reference [23 (link)]. ESI–TOF–MS m/z calculated for C₁₆₃H₂₄₉N₄₄O₄₇⁵⁺ [M + 5H]⁵⁺ 714.9684 found 714.9686. TH59-DB was resuspended in N, N-dimethylformamide (DMF) (043-32361, Wako) and kept in the freezer until use.

All reagents were purchased commercially and were of reagent grade. The AB-Lac polymer, PSar₁₀₆-block-PLLA₃₂ (molecular weight: 10,001) (Figure 1A), was synthesized by KNC Laboratories, Co., Ltd. (Kobe, Japan). o-Carborane, m-carborane, p-carborane, diC1-Carb, diC6-Carb, and diC12-Carb (Figure 1B) were purchased from Katchem, Ltd. (Prague, Czech Republic). ¹⁰B-BPA was purchased from Interpharma Praha, a.s. (IPP) (Prague, Czech Republic). RPMI-1640 medium, Dulbecco’s modified phosphate buffered saline (DPBS), chloroform, N, N-dimethylformamide (DMF), and nitric acid (HNO₃) were purchased from Fujifilm Wako Pure Chemical Corp. (Osaka, Japan). Dimethyl sulfoxide (DMSO) and fetal bovine serum (FBS) were purchased from Sigma-Aldrich, Co., Ltd. (St. Louis, MO, USA). B standard solution, penicillin–streptomycin mixed solution, and the trypsin (2.5 g/L)-EDTA (1 mmol/L) solution were purchased from Nacalai Tesque, Inc. (Kyoto, Japan). The Cell Counting Kit-8 (CCK-8) was purchased from Dojindo Molecular Technologies, Inc. (Kumamoto, Japan).