a crystallization tray includes a plurality of crystallization cells , each cell having a reservoir adapted to receive an equilibrating solution , a shelf located adjacent to the reservoir and adapted for use as a temporary cryogenic holding area for a crystallized substance and / or a sample holding area , and a sample drop receptacle carried by the shelf and adapted to receive a sample drop including a crystallizable substance . a related method for forming macromolecular crystals includes dispensing an equilibrating solution in the reservoirs , dispensing a plurality of macromolecular solution droplets in the sample drop receptacles , covering the cells with a cover ; and crystallizing the crystallizable substance by vapor diffusion .