Northern analysis of SHIP RNA expression. PolyA⁺ RNA from human bone marrow cells and from the previously characterized murine FDC-P1 cells was subjected to Northern blot analysis with a human SHIP cDNA probe. The blots were washed at a stringency of 1× SSC, 0.1% SDS at 55°C. Under more stringent washing conditions (0.1× SSC, 0.1% SDS at 65°C), the murine signal was lost but both human mRNA species remained (not shown). The FDC-P1 lane was exposed much longer than the HuBM lane.