From owner-cellbiol@net.bio.net Sat Dec 07 22:00:00 1996 Path: biosci!agate!ihnp4.ucsd.edu!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!torn!hone!informer1.cis.McMaster.CA!roger.interlynx.net!usenet From: "Lars Thomsen" Newsgroups: bionet.cellbiol Subject: Re: picospritzer Date: 8 Dec 1996 06:16:08 GMT Organization: 115 South Oval Lines: 24 Message-ID: <01bbe4cf$23cb2660$0ec032cc@boris.gate2.interlynx.net> References: <32A748F4.3067@neuro.biol.ethz.ch> NNTP-Posting-Host: ppp04-max1.interlynx.net X-Newsreader: Microsoft Internet News 4.70.1155 The Picospritzer is not really made for microinjection (or at least not suitable for it). It is much better for fast application of agonist/antagonist in e.g. single cell current or voltage clamp measurements. I think that you will have a hard time calibrating the exact volume that it will inject in a certain time. The calibration procedure described for the picospritzer is described as the time it takes to aschieve a certain concentration around a cell. You want a certain volume, thats not the same. You should get a displacement apparatus instead - I have one from Sutter Instruments and it will inject a given volumen that you specify on a digital display. If you really want to use it then you can make e.g. 20 electrode (and hope that your puller is stable) and then eject the content a the electrode into a vial for a given time e.g. 10 ms and then do it a number of times and then weigh the vial and find the amount that you in average inject pr time. Marc Roos wrote in article <32A748F4.3067@neuro.biol.ethz.ch>... > We are in possesion of a picospritzer (spelling ?) microinjection > apparatus, but as usual no instructions. Can anyone tell me how one > calibrates for volume ? I realize this all depends upon pressure, > calibre of microinjection needle etc. I am interested in injecting > both antibody and DNA. For both I would like some measure of how much > I am delivering. Any help appreciated. > .