RT-PCR analysis for PSGL-1 and CD24 expression. cDNAs derived from HL-60, KS and SW2 cells were amplified with sequence-specific oligonucleotide primers specific for PSGL-1 or CD24. For internal control β-actin specific primers were used. The size of the expected bands for each product are indicated. Lane 1, HL-60 cells β-actin primer; lane 2, HL-60 cells CD24 primer; lane 3, HL-60 cells PSGL-1 primer; lane 4, KS cells β-actin primer; lane 5, KS cells CD24 primer; lane 6, KS cells PSGL-1 primer; lane 7, SW2 cells β-actin primer; lane 8, SW2 cells CD24 primer; lane 9, SW2 cells PSGL-1 primer.