Dear Vince and Colleagues, I have found it possible to eliminate those satellite droplets; the finding was quite by chance. The earlier version of the drop drive hardware was recently upgraded on the MoFlo, and this extended the available drop drive amplitude from 10 volt to virtual infinity (it can go over 110 v, but I stopped there). I describe what happens in the 1 to 30volts range. As the drive amplitude is increased from zero, the strobed image shows satellite drops of 1/50th diameter, alternating with the standard large drops. Increasing the drive amplitude further, leads to satellites which are re-absorbed into preceding or following droplets. As the amplitude is increased further, the interval required before reabsorption occurs decreases with rising amplitude of drive voltage. Next there is a stage where the satellites show as bulges (Ray Hicks' nipples?) on the forming break-off drop, but don't actually separate. Further amplitude increases result in clean droplets, with no suggestion of satellite production. This is where I set the drive value. For most other sorters, my recommendation is to drive the stream at near maximum voltage (short of causing too harsh a distortion envelope), to minimise satellite production at least. It also helps if the delay is minimal. There are sound arguments which support the idea that highest stability occurs at the "point" of shortest delay. Best regards, Bob Vincent Falco requests help: > > > 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.
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