Figure 1. Chemotactic activity of purified recombinant human SDF-1α.
Human SDF-1α was expressed in E.coli (circles) and sf21 insect cells (squares), and compared to that obtained from R&D Systems (triangles). Chemotactic activities of the purified proteins were determined by Jurkat cell transmigration assay. Data are presented as the mean of two separate experiments, and are fitted to sigmoidal curves.