Fig. 1.

Expression of FcαRI gene products in human platelets. (A) RT-PCR analysis of FcαRI mRNA in human platelets. Total RNA was isolated from the purified platelets from six individuals (Lanes 1, 2, and 4–7) or from the peripheral blood leukocytes of a healthy donor (Lane 3*, positive control for FcαRI mRNA). Platelet RNA was reversely transcribed, and FcαRI cDNAs were amplified by RT-PCR. The identity of FcαRI cDNA products in human platelets was confirmed further by direct sequencing. (B) Detection of FcαRI on the surface of human platelets. FcαRI was detected using anti-FcαRI mAb MIP8a (bold line) in flow cytometry analysis by comparing with the mIgG1 isotype control (dashed line). The inset shows the staining of FcαRI (bold line) compared with mIgG1 isotype control (thin line) on human neutrophils. This is representative of four independent experiments with at least four normal, healthy donors shown.