High Speed Sorting

Ruud Hulspas ruud-hulspas at Cytonome.com
Wed Jan 10 12:05:15 EST 2007

As far as doing this on a MoFlo, I know that it is very important to 
also make sure that no potential contamination stays behind in the 
valves (particularly when equipped with the manual cylindric valves) by 
regularly turning the valves during the chlorox run.
It's my experience that some detergent (like Fantastik) works better 
(more 'stuff' seems to come out) than chlorine and that it's better to 
avoid running ethanol (debris may get fixed to the tubing or inside the 
valves). Always do an extensive run with sterile water after the 
detergent/chlorox run (.. and keep turning those valves).
Never had any problems either, but still don't think that the FDA will 
accept the procedure for clinical applications where sorted human cells 
actually end up in a patient.


Dr. Ruud Hulspas, Ph.D.
Director of Cytometry
27 Drydock Ave
Boston,  MA 02210
phone: 617-330-5030 x226

I have been sorting bacteria using a MoFlo two or three times every 
week for approximately 3 hours per sort since last February and have 
had zero contamination issues. Afterward the sort, I run freshly 
prepared 10% Chlorox for one hour at high sample pressure though 
there have been times that I have done this for as little as 15 
minutes; still without any issues. I do pay particular attention to 
the cleanliness of the top of the bacteria sort sample tube so as to 
not have bacteria contact the o-ring that fits onto the sort tube.

Flow Cytometry Core Facility
Albert Einstein College of Medicine

On Jan 7, 2007, at 6:30 PM, Rbwadley wrote:

 > Dear Stephen,
 > I used to run a Moflo MLS High Speed Sorter at the
 > University of NSW, Australia. On any given day I
 > could sort and/or analyse bacteria, Giardia, mouse, rat, human 
 > cells or fungi.
 > In 3 1/2 years I did not have a single proven case
 > of cross contamination.
 > If you consider how a sorter (or analyser) works the
 > only part of the instrument that comes in direct
 > contact with the sample is the sample line. If the
 > sample line is properly cleaned (I used bleach for a
 > couple of minutes followed by distilled water for a
 > couple of minutes), there is no problem. I could
 > see a problem if the sample was left in the
 > instrument after it was shut down overnight, but I
 > would hope that scenario would never happen.
 > I currently run a FACSAria at MMRI in Brisbane, and
 > again, with even minimal cleaning between sorts I
 > find zero cross contamination, although my samples
 > here are limited to mouse or human cells.
 > Regards
 > Rob Wadley
 > > --------- Original Message --------
 > > From: Stephen.Rosenberg at jefferson.edu
 > > To: cyto-inbox <cytometry at flowcyt.cyto.purdue.edu>
 > > Subject: Hi Speed Sorting
 > > Date: 21/12/2006 05:14
 > >
 > > I was wondering the following. If people were
 > > utilizing a a high-speed sorter in order to
 > > sort bacteria, should one be concerned if they
 > > were to sort mammalian cells on the same
 > > sorter as to whether there could be any
 > > contamination of the mammalian cells by either
 > > bacteria themselves or by bacterial
 > > products,i.e.-endotoxins.
 > >
 > > Thanks
 > >
 > > Steve
 > ________________________________________________
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Whenever you find you are on the side of the majority, it is time to 
pause and reflect.
Samuel Clemens (1835-1910)

C. William King
Flow Cytometry Core Facility
Albert Einstein College of Medicine
1300 Morris Park Avenue, C309
Bronx, New York 10461

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