Solution 2 was prepared as a well solution and mixed. A droplet containing 2 \ml of solution 1 was delivered onto a cover slip; 2 \ml of solution 2 was added to the droplet without mixing.
Crystal plates were originally stored at room temperature for 1 week but no nucleation occurred. They were then transferred to 4 degrees C, at which temperature well formed single crystals grew in 2 days.
The dependence on pH for successful crystal growth is very sharp. At pH 7.4 only showers of tiny crystals grew, at pH 7.5 well formed single crystals grew, at pH 7.6 no crystallization occurred at all.