Stability of an AMA1-C1/Alhydrogel vaccine following CPG 7909 addition. Reducing silver stained SDS-PAGE gels are shown. Prior to CpG addition, a sample of vaccine was centrifuged and the supernatant loaded onto the gel (B and C, lanes 2). Clinical grade CpG containing phosphate was added (final concentration 1 mg/ml) to 2-yr old (A and B) or freshly prepared (C) 160 μg/ml AMA1-C1/Alhydrogel vaccine. A: Samples were analyzed at t=0 (lane 1) and after incubation at room temperature for 15 min, 30 min, 1 h, 1.5 h, 2 h, 3 h, and 4 h (lanes 2-8). B and C: Samples were taken at t=0 (lanes 3) and after storage for 6 h on ice at 0°C (lanes 4) and room temperature (lanes 5). For comparison, 1.8 μg (the amount of protein that would be present had all of it dissociated from Alhydrogel) of reference AMA1-C1 is in A lane 9, and 0.1 μg of reference AMA1-C1 is in B lane 1. Molecular weight markers are indicated in kDa.