The Douglas Vapor Batch Plate is designed for both microbatch and vapor diffusion (sitting drop) crystallization. It has 96 wells in the center and several reservoirs around the outside. The reservoirs can be used to preserve microbatch crystals by preventing drying out of the wells, or they can be used for simple vapor diffusion experiments where up to 96 wells are equilibrated against a single precipitant.
Hydrophilic (plasma treated) plates are recommended for small volume screening experiments.