I have just begun using Chimera on my Mac, and find that it will be able to produce the graphics that I need for publication and display purposes. I recently opened a pdb file of a protein that we study bound to DNA and used the depiction, nucleotides tool to render the DNA backbone as ribbons with the bases shown as slabs. I noticed a discontinuity in one of the DNA strands, which may be caused by the severe distortion of the DNA. I think that this also happened with a previous program that I used called SPOCK that I used to draw the DNA strands as worms. In that case I could repair the break by changing the settings for the connectivity distances. How would I repair the break in Chimera? Thanks for your help. Sincerely, Fred Gimble Frederick S. Gimble, Ph. D. Associate Professor Department of Biochemistry BCHM 315 175 S. University St. Purdue University West Lafayette, IN 47906 Telephone: (765) 494-1653 Fax: (765) 494-7897 Email: fgimble@purdue.edu