Analysis of the effect of TdT expression on the frequency of CSR as well as characteristics of Sμ-Sα recombination junctions resulting from the joining of DSBs with blunt ends. (j) Top: Schematic representation of the experimental design to analyze the effect of TdT expression on CSR in WT and Samhd1 KO cells. Bottom: Western blot analysis of the expression of TdT in WT and Samhd1 KO cells. Tubulin was used as a loading control. 