Fig. 69: Diffraction pattern from a crystal of the core particle of blue-tongue virus, BTV 1. Cell dimensions of the crystal are a = 754 Å, b = 796 Å, and c = 823 Å. Exposure time was 20 seconds, the number of recorded reflections are 50,300 and data extend to 3.5 Å resolution. The detector used was a 30 cm MarResearch image plate system (courtesy of D. Stuart).