Re: [ccp4bb] No diffraction

[Roger Rowlett]

As other have/surely will suggest, by all means try RT collection to establish if your crystals really diffract OK, or if your cryo conditions are killing them. We have lots of experience in our lab getting "beamstop" diffraction with certain samples when subjected to cryoprotection. Depending on the intensity of your home source (and its life-cycle age), small crystals may not be large enough to produce usable or visible diffraction. With our home source, we really need 0.3 mm crystals (larger if thin plates) to get usable diffraction. Cheers, _______________________________________ Roger S. Rowlett Gordon & Dorothy Kline Professor Department of Chemistry Colgate University 13 Oak Drive Hamilton, NY 13346 tel: (315)-228-7245 ofc: (315)-228-7395 fax: (315)-228-7935 email: rrowl...@colgate.edu On 1/26/2012 10:33 AM, Theresa H. Hsu wrote: Dear crystallographers I have a protein of 90 kDa forming dimers. Crystals formed with microbatch and vapor diffusion method in 24 hours but no diffraction at home source. Dissolved crystals was confirmed to be the protein with mass spec. Any suggestions to improve diffraction would be welcome. Thanking you in advance. Theresa