Would someone fill me in on the major differences between the first and second editions of Drenth's textbook "Principles of Protein X-ray Crystallograph" ? Thanks, Mark ------------ Dr. Mark A. Saper saper at umich.edu Biophysics Research Division University of Michigan Phone: (734) 764-3353 930 North University Ave FAX: (734) 764-3323 Ann Arbor, MI 48109-1055