Detection of SDF-1α and SDF-1β in MS-5 cells and in serum. (A) Culture supernatants from MS-5 cells produced in serum-free medium (8 mL), control serum-free medium (8 mL), cell lysates of MS-5 cells (1 × 106 cell equivalents), recombinant human SDF-1α (20 ng), and SDF-1β (20 ng) were subjected to immunoprecipitation with anti–SDF-1α plus anti–SDF-1β antibodies and immunoblotted with antibodies that recognize both SDF-1α and SDF-1β or antibodies that preferentially recognize SDF-1β. (B) Aliquots of recombinant SDF-1α and SDF-1β and serum from 2 healthy individuals (a and b; precleared with protein G) were subjected to immunoprecipitation with anti–SDF-1α plus anti–SDF-1β antibodies and the immunoprecipitates immunoblotted with antibodies that recognize both SDF-1α and SDF-1β.
