Hi again folks, Eric, I did not mention this product at first because I did not have the info at my fingertips. (also did not think you would be interested in having to buy anything but....) There is a company which makes a "large bead compatible" instrument (originally made to sort nematodes) which has been investigated here and seems to work. Union Biometrica US Headquarters 35 Medford Street, Suite 213 Somerville, Massachusetts 02143 Tel: 617-591-1211 Fax: 617-591-8388 Their website has changed since I last visited but there is still an overview of their system. http://www.unionbio.com/copastech_overview.html I had not realized how old this particular technology was until I found this page, http://www.cco.caltech.edu/~wormlab/iwm99/wm99p443.htm Automated sorting and dispensing of C. elegans to wells of microtiter plates CD Johnson1, R Clover1, B Reardon1, PB Krauledat2, AA Ferrante2, WP Hansen2 1 Axys Pharmaceuticals, NemaPharm Group, South San Francisco, CA. 2 Union Biometrica, Inc., Somerville, MA. For generating a large number of separate populations of worms, liquid cultures in the wells of microtiter plates use space more efficiently than do standard cultures on agar plates. At NemaPharm, we routinely grow worms in microtiter plates for a wide variety of procedures including both forward and reverse genetics experiments as well as for high-throughput chemical screening. To automate distribution of worms into microtiter plate wells, we have constructed a machine that efficiently sorts and dispenses live nematodes. The mechanism used for measuring nematodes is based, in principle, on the nematode counting machine built by Lou Byerly, Randy Cassada and Dick Russell in the early 1970's (1). Nematodes are suspended in liquid and passed though a narrow nozzle into the center of a rapidly flowing sheath current. The resultant shear forces straighten the animals and orient them parallel to the direction of flow. The straightened animals are then passed at high speed (~1 m/sec) through an orthogonal sheet of laser light where, in the current model, an in-line detector measures the attenuation of the laser light and an attached computer calculates the length of the nematode based upon time-of-flight through the beam. Below the detector, the worm-containing stream is deflected to waste by a air jet controlled by the computer that shuts off momentarily to deliver a selected animal to a well (distribution volume is 0.25 - 1 µl per worm). The current sorter/dispenser is capable of distributing 10 worms to the wells of 96-well plates in 2 minutes with a precision of ±0.7 worms. Distribution to 384 and 1536 well plates is also feasible with the current model. Machines with more sophisticated detecting and measuring capabilities are planned for the future. (1) Byerly, et. al. (1975) Rev Sci. Instrum., 46:517-522 Cheers, Sam Sam Witherspoon sw11527@gsk.com High Throughput Biology * Tel. 919-483-3078 GlaxoSmithKline R&D Page 919-857-7768 5 Moore Dr. Fax 919-483-0585 RTP, NC 27709 > -----Original Message----- > From: Nealley, Eric W Mr USAMRICD [SMTP:Eric.Nealley@apg.amedd.army.mil] > Sent: Wednesday, July 11, 2001 10:11 AM > To: Cytometry Mailing List > Subject: sorting large particles > > > Our group has been tasked to sort large diameter beads (180 um) which have > gone through a process to attach peptides. We suggested that a new > library > of smaller peptide labeled beads be used, but for now the group wants to > try > and make use of the larger beads until a new library can be created using > small beads. We have a FACStar Plus equipped with a 400 um nozzle (with > turbo sort option) and we have tried to align/standardize/calibrate with > little success. We have followed the BD macrosort procedure (lower sheath > psi and lower ddf) but again with little success. The only bead that I > currently have for alignment are flow check beads which are ~10 um (I > assume > at this point that 10 um beads are not the correct ones to use with the > large nozzle). I have ordered 100 um beads from FCSC. > > - Has anyone sorted using a 400 um nozzle? > - Has anyone successfully sorted ~180 um beads before? > - How do we align/calibrate/standardize the instrument? > > Thank you. > > Eric Nealley > Biologist, Pharmacology Division > Aberdeen Proving Ground, Maryland
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