Hi Horacio, we have a Cartesian Honeybee and perform trypsin-containing trials by setting up drops with a dedicated protein+trypsin tip, which we then wash extensively with water, 6 M guanidinium hydrochloride, then water, isopropanol and again water. hth, ciao, Sebastiano
On Jan 24, 2012, at 1:12 PM, Horacio Botti wrote: > Dear all > > We 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: ccp...@dl.ac.uk > Subject: [ccp4bb]: Crystallization robots and protease. > From: Marc Graille <marc.grai...@ibbmc.u-psud.fr> > Date: Mon, 19 Dec 2005 13:21:36 +0100 > Sender: owner-ccp...@dlmail1.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 > > > -- > patr...@douglas.co.uk 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 > > <hbotti.vcf> -- Sebastiano Pasqualato, PhD Crystallography Unit Department of Experimental Oncology European Institute of Oncology IFOM-IEO Campus via Adamello, 16 20139 - Milano Italy tel +39 02 9437 5172 fax +39 02 9437 5990
