Dear allWe may use a Honeybee 963 robot to screen crystallization conditions for trypsin-containing protein samples and we are worried about robot contamination by residual protease. How do you normally clean robots when using this kind of sample? Your suggestions/recommendations will be appreciated. Thks!!
Horacio Botti Unit of Protein Crystallography, Institut Pasteur of Montevideo, Uruguay. PS: below you have an old short CCP4 discussion: [ccp4bb]: Crystallization robots and protease. ------------------------------------------------------------------------ * /To/: [email protected] <mailto:ccp4bb%40dl.ac.uk> * /Subject/: [ccp4bb]: Crystallization robots and protease. * /From/: Marc Graille <[email protected] <mailto:marc.graille%40ibbmc.u-psud.fr>> * /Date/: Mon, 19 Dec 2005 13:21:36 +0100 * /Sender/: [email protected] <mailto:owner-ccp4bb%40dlmail1.dl.ac.uk> * /User-agent/: Debian Thunderbird 1.0.2 (X11/20050602) ------------------------------------------------------------------------ *** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk *** Dear all,I have a question regarding the use of robotics to screen for crystallization conditions for proteases. Does anyone have already used robots on proteases? If yes, have you experienced any protease "contaminant" in the robot pipes, which could have affected the results on other projects performed during the next few days ?? I mean that we cannot exclude that a "contaminant" could digest the protein we are working on and yield crystals of a fragment of the studied protein.
We are hesitating in using our crystallization robots on proteases as we are afraid to have some contaminant in the pipes that will disturb all our future experiments!!! Any advice about how to clean the robot syringes after use of proteases are welcome!!!
Regards, Marc -- Marc Graille, PhD Equipe de Genomique Structurale Institut de Biochimie et de Biophysique Moleculaire et Cellulaire (IBBMC) CNRS UMR8619 Bat 430 Universite Paris Sud 91405 Orsay Cedex Tel: 0169155047 *** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk *** Dear Marc We recommend cleaning dispensing tips with Hellmanex II from the German company Hellma. It's for cleaning cuvettes. You can buy it from VWR and others. Hellmanex is a mildly alkaline solution with surfactants etc. It has no enzymes in it, but you do need to flush with buffer to get rid of the alkali. Previously, users reported that cleaning with methanol mixed with concentrated HCl worked very well in extreme cases. Our robot, the Oryx, uses only one tip for protein. This is semi-disposable. Using one tip and touching off the drops has the great advantage that virtually no protein is wasted, and drops as low as 20 nl can be dispensed, even containing 50% glycerol! We recommend that users keep tips that have been used for proteases separately, and clean them after use. (The system comes with 8 tips and replacements cost 45 USD.) Also we recommend that tips are thoroughly cleaned once a fortnight for average use in any case. I hope this is helpful. Sincerely Patrick-- [email protected] Douglas Instruments Ltd. DouglasHouse, EastGarston, Hungerford, Berkshire, RG177HD, UK
Directors: Peter Baldock, Patrick Shaw Stewart, James Smith http://douglas.co.uk or http://www.douglasinstruments.com Tel: 44 (0) 148-864-9090 US toll-free 1-877-225-2034
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