Lanes 1 - 2 : anti-SHP1 (C-terminal) Lanes 3 - 6 : Anti-SHP1 (phospho S591) antibody (ab41436) at 1/1000 dilutionLane 1 : human Jurkat cells treated with 1 mM pervanadate for 30 min. Lane 2 : human Jurkat cells treated with 1 mM pervanadate for 30 min, blot exposed to lambda phosphatase before probing Lane 3 : human Jurkat cells treated with 1 mM pervanadate for 30 min. Lane 4 : human Jurkat cells treated with 1 mM pervanadate for 30 min, blot exposed to lambda phosphatase before probing Lane 5 : human Jurkat cells treated with 1 mM pervanadate for 30 min. with phospho-Ser591-SHP1 peptide Lane 6 : human Jurkat cells treated with 1 mM pervanadate for 30 min. with non specific phospho-serine peptide