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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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CD-ROM Vol 3 was produced by Monica M. Shively and other staff at the
Purdue University Cytometry Laboratories and distributed free of charge
as an educational service to the cytometry community.
If you have any comments please direct them to
Dr. J. Paul Robinson, Professor & Director,
PUCL, Purdue University, West Lafayette, IN 47907.
Phone: (765)-494-0757;
FAX(765) 494-0517;
Web