Quantification of integrin α₂ mRNA. Platelet total RNA was extracted, reverse transcribed into cDNA, and amplified in an ABI Prism 7700 Sequence Detector. Platelet integrin α_IIb was the internal control used to normalize results between samples. Results are expressed as the fold-difference in α₂ mRNA expression in platelets from FVB mice. Data are the means ± SD of 4 separate experiments starting at the RNA extraction.