Native Elongin A Co-IP on mouse embryonic stem cells nuclear extract using R19 goat EloA antibody

To identify proteins associated with mouse Elongin A (EloA), we carried out Co-IP on nuclear extract prepared from mouse ES cells from wild-type and null Elongin A cells (negative control).Each immunoprecipitation was excised as 5 gel
sections, minced and digested in-gel using trypsin. Electroionization was performed on the peptides before entering an LTQ Orbitrap Velos Pro ion trap mass spectrometer instrument (Thermo Fisher Scientific). Sequest (Thermo Finnigan, San Jose, CA) was used for identification of the peptide sequences. Identified peptides were filtered by false discovery rate of 1% or less. Processing, preparation, and Mass spectrometry analysis of the samples was carried out at Taplin Mass Spectrometry Facility (Harvard Medical School).