Validation of PLA on pre-B lymphoblasts. a Quantitative real-time RT-PCR and western blot analysis showed respectively mRNA and protein expression of RUNX1, ETV6 or ETV6-RUNX1 in Nalm6 and REH cells. All RT-PCR (left panel) were performed in triplicate and gene expression was normalized to ABL1 expression (error bars are S.D.) while western blot analyses (right panel) are representative images from the whole-cell lysates. b Technical controls demonstrate the specificity of PLA signals in Nalm6 cells and the proximity between two proteins (RUNX1 and CBFB). Nuclei were stained with DAPI. RUNX1 ab110035 antibodies were incubated alone (−) or with RUNX1 ab23980, CBFB ab133600 or ETV6 sc11382 antibodies. Each picture (upper panel) is representative of a typical cell staining observed in 5 fields randomly chosen. The quantification of the number of PLA dot per nucleus is presented with the mean values ± S.D