A method to produce microseed stock for use in the crystallization of biological macromolecules

A method is presented for producing a seed-stock mixture for macromolecular crystallization. A PTFE bead and micro­centrifuge tube act as mortar and pestle for pulverizing seed crystals of macromolecules. Energy for the bead's motion is supplied by a vortex mixer or an ultrasonic bath. The crushed crystal is serially diluted to prepare a seed-stock mixture of the desired concentration for crystallization. Crystals produced using both hanging-drop vapor diffusion and a capillary microbatch method show expected dilution behavior. This technique of producing seed stock is compared with traditional means and advantages over the standard protocol are demonstrated.