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Dear Prerana, Seeding is best suggestion. Use your current crystals as seed for a fully new crystal screen. This really helps. I myself have used crystal seed for screening and got the crystal almost in every condition. Good Luck Pankaj On Thu, Sep 3, 2015 at 9:24 AM, Patrick Shaw Stewart <[log in to unmask]> wrote: > > Hi Perana > > You say you have tried seeding. Have you tried adding concentrated seed > stocks to *random* screens, the so-called MMS or rMMS method? > > Your crystals look nice, and there is a good chance that you can pick up > new conditions that diffract well within a couple of plates. Use random > screens that you have used before with your particular protein, then you > will be able to identify conditions that *only* give crystals when you > add seeds. In those conditions you will have much more control - you can > control the number of crystals by diluting the seed stock. > > The approach can roughly double the number of structures that your lab > produces - see slide 5 of > http://hamptonresearch.com/documents/ramc/RAMC2011_T11_Obmolova.pdf . > Other refs below. > > If you let me have your postal address we'll send you a microseeding > "toolkit". > > Best wishes and good luck, Patrick > > __________________ > > > [1] D'Arcy, Allan, Frederic Villard, and May Marsh. "An automated > microseed matrix-screening method for protein crystallization." *Acta* > *Crystallographica Section D: Biological Crystallography* 63.4 > (2007): 550-554. > > [2] Obmolova, G., Malia, T. J., Teplyakov, A., Sweet, R. W., & Gilliland, > G. L. (2014). Protein crystallization with microseed matrix screening: > application to human germline antibody Fabs. *Structural Biology and * > *Crystallization Communications,* 70(8). > > [3] Further information on the theory and practice of the MMS > method is available at the Douglas Instruments web-site, > *http://www.douglas.co.uk/mms.htm <http://www.douglas.co.uk/mms.htm> *and > > *http://www.douglas.co.uk/MMS_proc.htm > <http://www.douglas.co.uk/MMS_proc.htm>* > > [4] Vera, L., Antoni, C., Devel, L., Czarny, B., Cassar-Lajeunesse, E., > Rossello, A., ... & Stura, E. A. Screening using polymorphs for the > crystallization of protein-ligand complexes. *Crystal Growth & Design. * > 13(5), 1878-1888. > > [5] Abuhammad, A., Lowe, E. D., McDonough, M. A., Shaw Stewart, > P. D., Kolek, S. A., Sim, E., & Garman, E. F. (2013). Structure of > arylamine N-acetyltransferase from Mycobacterium tuberculosis > determined by cross-seeding with the homologous protein from M. > marinum: triumph over adversity.*Acta Crystallographica Section D: * > *Biological Crystallography*, *69*(8), 1433-1446. > > [6] Shaw Stewart, P., & Mueller-Dieckmann, J. (2014). Automation in > biological crystallization. *Acta Crystallographica Section F: > Structural * > *Biology Communications*, *70*(6), 686-696. > > [7] Shaw Stewart, Patrick D., et al. "Random microseeding: a > theoretical and practical exploration of seed stability and seeding > techniques for successful protein crystallization." *Crystal Growth &* > *Design* 11.8 (2011): 3432-3441. > > > > On 1 September 2015 at 07:27, Prerana G. <[log in to unmask]> wrote: > >> Dear all, >> >> I am working on a protein (~36kDa) which forms small crystals which >> diffracts at very low resolution. Protein concentration that I have used >> for crystallization is approx. 8mg/ml. I have already tried seeding though >> the improvement in size of the crystal was minimal. I have attached the >> picture of the protein crystal. >> >> How can I improve upon the size of the crystal? >> >> >> Prerana >> > > > > -- > [log in to unmask] Douglas Instruments Ltd. > Douglas House, East Garston, Hungerford, Berkshire, RG17 7HD, UK > Directors: Peter Baldock, Patrick Shaw Stewart > > http://www.douglas.co.uk > Tel: 44 (0) 148-864-9090 US toll-free 1-877-225-2034 > Regd. England 2177994, VAT Reg. GB 480 7371 36 >