Liquid nitrogen cryospray for biological applications

One of the methods to study three-dimensional protein structures is via X-r ay diffraction techniques. Radiation damage produced by the interaction of X-rays with the sample can be reduced by soaking the protein crystals in cr yoprotectants and freezing them at liquid nitrogen temperature. The perfect ion of the frozen crystals depends critically on the choice of cryoprotecta nt, and the rate of freezing. We have developed a device to produce a fine spray of liquid-nitrogen droplets smaller than 10 mu m in order to increase the rate of freezing. (C) 2000 Elsevier Science B.V. All rights reserved.