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The Gilson crystallisation robots (horrible machines: no longer available) were specific for hanging drops - other robots can set them up (using the Mosquito sheets or equivalent), but the flipping will have to be done by hand. The Douglas Instrument machines can basically pipette onto anything you want, as it is a one-by-one dispense. You still have to flip by hand. The Mosquito has the ability to do a 'mirror' transfer - which makes the setup of hanging drops easy, as it compensates for the inversion that you necessarily get when you flip the piece of plastic (it's a good idea to flip the plastic around the same axis as the mirror function, BTW). If you want to use this arrangement on the phoenix then you will need to make up a plate or block with the crystallisation solutions mirrored, and set up a protocol where the normal array is transferred from the storage block into the experimental plate reservoirs, and then the mirrored array of crystallisation solutions is used to make up the crystallisation droplets. Certainly do-able, but it means that you need TWO source blocks for each screen that you want to set up this way. Best of luck keeping that working in a multi-user lab! We have both a Mosquito and a Phoenix (and an older Cartesian 16+1), and I could not recommend one over the other of the first two machines - they are both easy to use, but they do different things well. The Mosquito can deal with difficult samples (protein which is crashing out of solution, for example). We have been able to set up protein which gelled to the consistency of hair-gel with our gnat. The Phoenix does not dispense viscous samples well from the nano-tip (anything over 10% glycerol is really iffy, for example), but doesn't require the protein to be aliquoted out into 8 separate puddles. The Cartesian was always a bitch to get running, so given the other two machines, it sits and collects dust. Anybody want to start negotiating for a (slightly) used Cartesian? Janet Janet Newman CSIRO Molecular and Health Technologies 343 Royal Parade Parkville VIC 3052 Australia tel: +61 (0)3 9662 7326 fax: +61 (0)3 9662 7101 email: [log in to unmask] _____ From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of Lisa A Nagy Sent: Thursday, 10 January 2008 4:49 AM To: [log in to unmask] Subject: Re: [ccp4bb] crystallization robot The phoenix can dispense multiple drops per well. You can easily program dispensing on the deck wherever, whatever and whenever, as long as it fits in the plate holder . It can handle at least the 1536 pitch (4 x 384), so if you specify the quadrant of the 384 well cell it will dispense there. Your drops may merge, though. It has a separate dispensing head for proteins or additives. You can dispense from up to 16 "protein" tubes (chilled) and 2 ambient tubes, plus whatever is on the deck, in whatever order you want. Since the setup programming is an easy gui, it's not a big deal. I am certain that the mosquito sheets would work on any robot. From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of Van Den Berg, Bert Sent: Wednesday, January 09, 2008 11:00 AM To: [log in to unmask] Subject: Re: [ccp4bb] crystallization robot The mosquito has special (albeit fairly pricey at $13 each) plastic sheets that allow setup of hanging drops in a 96-well format. It can also do multiple drops per well. As far as I know this is a capability unique to the Mosquito but I may be wrong. Bert van den Berg University of Massachusetts Medical School Program in Molecular Medicine Biotech II, 373 Plantation Street, Suite 115 Worcester MA 01605 Phone: 508 856 1201 (office); 508 856 1211 (lab) e-mail: [log in to unmask] http://www.umassmed.edu/pmm/faculty/vandenberg.cfm _____ From: CCP4 bulletin board on behalf of Lisa A Nagy Sent: Wed 1/9/2008 11:53 AM To: [log in to unmask] Subject: Re: [ccp4bb] crystallization robot Looking at the mosquito, it doesn't have any cover-slip handling robotics, either. So it's the same thing- rearrange the dispense location and flip the cover- which is either a glass plate or mylar or a tape seal. -- Lisa Nagy University of Alabama-Birmingham [log in to unmask]