*** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk ***
Hi Brian, you might find the article by Forsythe et al. entitled "Vapor diffusion, nucleation rates and the reservoir to crystallization volume ratio" [Acta Cryst D58:1601-1605] quite revealing. The authors show data that a droplet to reservoir volume ratio of 1:9 will eventually result in a 95% equilibation of the droplet. Of course, how fast that happens will depend on a number of other parameters. Your ratio of 33-fold excess will result in a 98% equilibration of the droplet according to the plot in figure 3 of that article. Best wishes Savvas -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brian Mark Sent: dinsdag 11 april 2006 2:00 To: [email protected] Subject: [ccp4bb]: Protein crystallization *** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk *** This is a non-CCP4 related question, but one that perhaps other CCP4 users might be concerned with as well. We've just switched to 96-well plates to set up our crystallization screens, using 8-channel pipettes to array out the mother liquor and set up the drops. We can go down to about 1.5 ul protein/1.5 ul mother liquor drops with accuracy, and currently use 100 ul of mother liquor/well. This gives only ~33 times the volume of mother liquor to drop volume per well when initially set up. This ratio seems small compared to 24-well plates where it's easy to ensure a much larger excess of mother liquor. Although a 33 fold excess seems like it should be enough for sufficient vapour diffusion to occur, does anyone who has experience with 96 well plates say otherwise?? Thanks in advance, Brian ------------------------------------------------------- Brian L. Mark, MSc, PhD Department of Microbiology Room 418, Buller Building University of Manitoba Winnipeg, Manitoba CANADA R3T 2N2 Phone (204) 480-1430 Fax (204) 474-7603
