Aggregation response of platelets derived from α_IIb^+/+, α_IIb^+/−, and α_IIb^−/− mice.

Platelets diluted with PBS at a final concentration ranging from 0.5 to 1 × 10⁸ in 336 μL were mixed with 14 μL CaCl₂ (1 mmol/L final) and placed in an aggregometer (Chrono-log) at 37°C. Aggregation was initiated by the addition of 18.5 μL ADP (final concentration, 10 μmol/L) or 39 μL collagen (final concentration, 0.2 mg/mL) from Sigma (diagnostic kit for aggregation). Aggregation was monitored by recording the increase in light transmittance as a function of time.