Fig. 3.

A 24-well plate in which either (a) sitting-drop or (b) hanging-drop vapor diffusion is done. The well solution (colored red) is mixed in equal proportion with protein solution (colored blue). In the sitting-drop technique, the resulting mixture sits on a pedestal above the well solution and the top of the chamber is sealed with grease and glass. In the hanging-drop technique, the mixed drop is included on the glass slide itself, inverted and sealed with grease atop the chamber.