| X-RAY DIFFRACTION |
6.0 |
? |
Microcrystals are obtained by dissolving 0.025 g protein in 5 mL of crystallizing solution (200 mL 0.02 M HCl, 100 mL 0.20 M sodium citrate, 60 mL acetone, 20 mL water, 20 mL 0.12 M zinc sulfate) at 315K. The solution is then rapidly quenched to 293K by immersing it in a cool water bath. Quenching speed determines the resulting crystal size. 20-micron crystals are obtained by quenching in a 293K water bath, 10-micron crystals by quenching in a 283K water bath, and 5-micron crystals by quenching in ice water. pH 6.0, SMALL TUBES |