Hypoxia/normoxia protocol to study effects of ARC5690 on sickle RBC and leukocyte adhesion. SCD mice were injected with saline, ARC5690 or ARC5694. Two and one-half hours after injection, mice were subjected to 1 hour of hypoxia (FiO2 = 0.12) followed by 1 hour of normoxia in room air (FiO2 = 0.21), and intravital studies were then initiated. During surgery, mice were supplemented with 30% O2. FiO2 indicates fraction of inspired oxygen in a gas mixture.