Copyright information:Taken from "Characterization of the SECIS binding protein 2 complex required for the co-translational insertion of selenocysteine in mammals"Nucleic Acids Research 2005;33(16):5172-5180.Published online 9 Sep 2005PMCID:PMC1214547.© The Author 2005. Published by Oxford University Press. All rights reserved Both XH-CTSBP2 and GST-CTSBP2 were co-expressed in and crude extracts were passed over a glutathione agarose column. Fractions were tested for GST-CTSBP2 content by SDS–PAGE and Coomassie staining. Each fraction was also tested for the presence of XH-CTSBP2 by western analysis using an anti-Xpress tag antibody. Lane 1 shows 20 ng of recombinant XH-tagged SBP2 purified on Nickel-agarose from the co-expressing strain.