Maintaining a consistant trajectory when sorting multiple droplets is tricky due to the interaction among the charged droplets and satellite stream segments. It can be variable among samples due to the deformation of the droplets that actually contain cells. If a cells(s) is large enough to affect the droplet shape or is located near the droplet pinch off then the droplet containing the cell will deform slightly, changing its surface thus affecting its interaction with adjacent droplets. Instead of multidrop sorts you might want to try reducing the droplet formation frequency a little and doing single drop sorts. We have done similar sorts onto filters using 25 kHz droplet generation frequency and single droplet sorts. We get a much tighter droplet trajectory with this setup. This works especially well if your sorter allows you to cells based on the phase relationship of their arrival with the sort charge pulse (i.e. require that the cell be in the center 60% of the sort pulse). gary Vincent Falco laments: > > > My problem is this:During some sorts I get ,what I will call a spurious extra > drop. To explain more,there are times I sort to polycarb filters.When all is > well I get a single spot which contains the desired cell population.When all > is supposed not well I get my desired single spot with cells and just about a > quarter of inch from the desired spot I observe a spurious spot,which does > not contain the desired cells. Gary Durack University of Illinois Biotechnology Center voice (217) 244-0559 fax (217) 244-0466 durack@uiuc.edu http://www.life.uiuc.edu/biotech
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