Co-immunoprecipitation of selected proteins with the eYFP-WRN construct. Human 293 embryonic kidney cells were transfected with an eYFP or a eYFP-WRN expression vector. Whole cell extracts (WCE) were immunoprecipitated with an anti-eYFP antibody (IP α-YFP). The immunoprecipitate was analyzed by immunoblotting with antibodies against POLR2A, POLR2B, HNRPK, MSH2, XRCC1 Lamin B1, and nucleophosmin. Panels on the left represent the immunoprecipitation performed in the absence of nuclease. Panels on the right represent the immunoprecipitation performed in the presence of Benzonase and RNase A in the lysis buffer.