Table 1. Size comparison of crystals grown via conventional hanging-drop experiments versus crystals grown on Roadrunner II chips using the same crystallization condition.
In all cases protein solutions were mixed with precipitant solutions in a 1:1 ratio. The volumes used for the drop and the reservoir were 6 and 500 µl for the hanging-drop experiments and 100 µl and 5–7 ml for the on-chip crystallization experiments, respectively. Unless otherwise stated, crystallization experiments were performed at room temperature.
| Sample | Crystallization condition | Hanging-drop crystals | On-chip crystals |
|---|---|---|---|
| hAQP2 (Homo sapiens) | 9 mg ml−1 protein, 0.1 M Tris pH 8.5, 0.1 M NaCl, 0.1 M MgCl2, 10 mM CdCl2, 22–25% PEG 400 | Different shapes and sizes, ranging from small needles to blocky rods | Different shapes and sizes, ranging from small 10 µm needles to larger 20 × 250 µm needles and up to 50 × 150 µm blocky rods |
| CODH (Oligotropha carboxidovorans) | 19.3 mg ml−1 protein, 0.75 M KH2PO4/KOH pH 7.5, 0.75 M NaH2PO4/NaOH pH 7.5, 94 mM HEPES/NaOH pH 7.5, 3% MPD at 4°C | 50–100 µm wide, blocky, rod-shaped | 50–100 µm wide, blocky, rod-shaped |
| Lysozyme (Gallus gallus) | 80 mg ml−1 protein, 0.1 M sodium acetate pH 4.8, 12% NaCl, 20% ethylene glycol | 50–170 µm, cuboid | Up to 170 µm, cuboid |
| Lysozyme (Gallus gallus) | 60 mg ml−1 protein, 50 mM sodium acetate pH 3.5, 0.75 M NaCl, 30% ethylene glycol, 11.25% PEG 400 at 4°C | Up to 180 µm, cuboid | Up to 170 µm, cuboid |
| Proteinase K (Tritirachium album) | 20 mg ml−1 protein, 0.1 M CHC buffer pH 6.5, 10 mM CaCl2, 0.7 M ammonium sulfate | 40–50 µm, rhomboid | Up to 80–125 µm, rhomboid |
| Thaumatin (Thaumatococcus daniellii) | 10 mg ml−1 protein, 0.1 M ADA pH 6.5, 0.9 M sodium/potassium tartrate | Up to 140 µm, rhomboid | Up to 120 µm, rhomboid |
| Thermolysin (Geobacillus stearothermophilus) | 22.5 mg ml−1 protein, 0.1 M MES–NaOH pH 6.5, 10 mM CaCl2, 5% PEG 2000 | Up to 60 × 300 µm, rod-shaped | Up to 60 × 320 µm, rod-shaped |