Hi Eswar Firstly, I would certainly try crystal seeding into random screens if you haven't already tried it. Refs below.
Secondly, it's very convenient to grow the crystals under oil, and to soak the organic solvents into the drops, through the oil. This makes it much easier to harvest the crystals because the oil becomes saturated with the solvent and stops it from evaporating when you pick up the crystals. This approach can be used at the screening stage too. See Mortuza, et al. High-resolution structure of a retroviral capsid hexameric amino-terminal domain. Nature 431 (2004), pp 481-485. Also see http://www.douglas.co.uk/winner1.htm Good luck Patrick ________ Allan D’Arcy, Frederic Villarda, May Marsh. 'An automated microseed matrix-screening method for protein crystallization'. Acta Crystallographica section D63 (2007) 550–554. On-line at http://scripts.iucr.org/cgi-bin/paper?S0907444907007652 A. G. Villaseñor, A. Wong, A. Shao, A. Garg, A. Kuglstatter and S. F. Harris. 'Acoustic matrix microseeding: improving protein crystal growth with minimal chemical bias.' Acta Crystallographica Section D66 (2010) 568-576. On-line at http://scripts.iucr.org/cgi-bin/paper?S0907444910005512 Galina Obmolova,* Thomas J. Malia, Alexey Teplyakov, Raymond Sweet and Gary L. Gilliland. 'Promoting crystallization of antibody–antigen complexes via microseed matrix screening.' Acta Crystallographica Section D66 (2010) 927–933. Open-access at http://journals.iucr.org/d/issues/2010/08/00/bw5361/bw5361.pdf Patrick D. Shaw Stewart, Stefan A. Kolek, Richard A. Briggs, Naomi E. Chayen and Peter F.M. Baldock. 'Getting the most out of the random microseed matrix-screening method in protein crystallization'. Cryst. Growth Des., 2011, 11 (8), pp 3432–3441. On-line at http://pubs.acs.org/doi/abs/10.1021/cg2001442 See also http://www.douglas.co.uk/mms.htm On Fri, Aug 26, 2011 at 11:55 AM, eswar reddy <eswar.uo...@gmail.com> wrote: > > Dear All > I was working on a Human protein and expression and > solubility is good in E.coli and purification is One step (His-Tag), and i > need to cleave the Histag before screens, if not > the protein will precipitated and Aggregated, but after trying for 1.2 years > i have crystals and they are with Organic solvents, (10 conditions), these > crystals are inter grown like broccoli shaped and i tried seeding, but it > is not successful, and even i tried with additive screen but the result is > the same .... is there is any idea to increase the size and shape of > my protein crystals. > Any suggestions will be helpful for me > Thanks in Advance > > -- patr...@douglas.co.uk 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
