50,000 cells were washed with PBS and resuspended in transposition reaction buffer with Tn5 transposase and digitonin and incubated at 37degrees for 30mins with shaking. DNA was subsequently purified using the Qiagen Enzymatic Reaction Clean-up kit. Nextera PCR primers were added during PCR amplification of transposed DNA fragments for an appropriate number of cycles determined for each library. Samples were purified using Qiagen Minelute clean-up kit and Ampure beads.