GST pull-downs. Lysates from FDC-P1 cells were either untreated (−) or treated with M-CSF (+) as for Fig 7. Lysates were immunoprecipitated with anti-p85 or anti-SHIP #5340 polyclonal antibodies (IP), or were mixed with GST-agarose beads and purified peptides representing either the N-terminal or C-terminal SH2 domains of p85 fused to GST (GST). Beads were incubated and washed and the eluted proteins subjected to immunoblotting with MoAbs P1D7 or P2C6.