In addition to the other useful advice offered, I’d also suggest determining if the whole complex or just the DNA fits in the asymmetric unit. Particularly if the crystals are hexagonal rods or plates, you might have DNA-only crystals.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Phoebe A. Rice Dept. of Biochem & Mol. Biol. and Committee on Microbiology https://voices.uchicago.edu/phoebericelab/ From: CCP4 bulletin board <CCP4BB@JISCMAIL.AC.UK> on behalf of Natalia O <natalie.c...@gmail.com> Reply-To: Natalia O <natalie.c...@gmail.com> Date: Friday, March 2, 2018 at 7:35 PM To: "CCP4BB@JISCMAIL.AC.UK" <CCP4BB@JISCMAIL.AC.UK> Subject: [ccp4bb] does 12 A diffraction worth optimization Hello, I got crystals of protein-nucleic acid complex, rod-shape, reproducible, don’t visibly get damaged upon freezing; however they gave diffraction only to about 12 A. I tried several crystals. My question is whether such crystals worth optimization. Clearly a 4A diffracting crystal could potentially be optimized to 3 – 2.5A, but if the diffraction that I am getting now is 12A it could suggest that the system is so flexible that getting to 3A with this crystal form is not possible at all. I just wonder if there is any statistics or a rule of thumb about what initial diffraction worth optimization? Thank you! -Natalia
