Re: Sorting Question

From: Steve G. Hilliard (steve@habanero.cb.uga.edu)
Date: Fri Jun 20 1997 - 07:35:10 EST


Vincent,

It certainly sounds like amplitude could be the problem, because that 
would affect degree of deflection.  I don't have any brilliant 
suggestions, but I would be tempted to clean (abrasive, maybe a pencil 
eraser) the plate leads, to ensure good electrical contact.  Does the extra 
drop contain any cells?  (Duhh--if it didn't I guess you wouldn't be
worrying about it.)  On my Cicero system I can adjust charge phase, which 
seems to tighten up my droplet puddles--maybe this would help.

Of course if amplitude drifts then it doesn't matter how good it looks at 
first.....how long do you let it warm up?  Mine seems to be ready about 4 
in the afternoon ;-( especially if I need to sort for several hours.

Steve, hoping that others will be more helpful...
-------------------------------------------------------------
Steve G. Hilliard                   Linux:   In a world 
Cell Analysis Facility                 without fences, 
University of Georgia                  who needs Gates?
-------------------------------------------------------------

On Thu, 19 Jun 1997, Vincent Falco wrote:

> 
> 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.I maintain the nozzle on a strict PM cleaning 
> schedule and watch for clogs etc.during times of sorting.The drive frequency 
> remains constant during a sort and is generally consistent day to day.The 
> amplitude level requires adjustment during a sort run.Should I be suspect 
> that the amplitude level is giving the problem? Can anyone suggest other 
> potential problem areas.Can anyone give rules/guidelines they follow when 
> establishing drop drive frequency and amplitude level?Thanks.
> 



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