Figure 1.

Expression and purification of Flag-sTALL-1. (a) Expression of Flag-sTALL-1. 293 cells were transfected with pSec-Flag-sTALL-1 or an empty control plasmid. Twenty-four hours after transfection, cell culture medium was collected and immunoprecipitated with a monoclonal anti-Flag antibody (lanes 2 and 4) or mouse IgG control (lanes 1 and 3). The immunoprecipitates were analyzed by Western blot with anti-Flag antibody. (b) Purification of Flag-sTALL-1. Conditioned medium from a 293 stable cell line expressing Flag-sTALL-1 was passed through an anti-Flag affinity column. Bound proteins were eluted with Flag peptide and analyzed by Coomassie blue staining (left lane) or Western blot with anti-Flag antibody (right lane).