SHIP competitive PCR. (A) cDNA from WEHI-3 cells, FDC-P1 cells, and BMM was amplified for the specified number of cycles using the 2666-3247 primer set. Products were transferred to a membrane and hybridized using a ³²P-labeled SHIP cDNA sequence common to both. (B) The signal of each band was measured using a Phosphorimager and plotted against cycle number. Within the linear range of amplification, cycles 26 through 32, the 398 bp ▵183 SHIP band (○) from each cDNA type was compared with the 581 bp full-length SHIP band (•) in the same lane.