Peter A. Lopez 970.226.2200
Cytomation,Inc. 400 E. Horsetooth Rd. Ft.
Collins,CO USA
Manager, Applications Laboratory PeterL@cytomation.com
> ----------
> From: Peter Lopez
> Sent: Tuesday, October 21, 1997 9:21 AM
> To: Nigel M. Ferrey; John Drennen; John Griffin; Luis A Cantarero
> Cc: Peter Lopez
> Subject: FW: Staining of Whole Blood.
>
>
>
> Hello
>
> I wanted to address some of the information being seen here
> in response to the comment by my fellow Cytomate Bob Ashcroft about
> high-speed analysis. Bob is very enthusiastic when speaking about the
> potential of MoFLo, as are the users of the instrument.
> It is clear that analysis of whole blood can be performed on any
>
> instrument using alternate thresholding techniques. I was wondering if
> anyone
> could comment on depletion of antibody titer by nonspecific binding to
> RBC's-
> I seem to remember some discussion on this topic in the past, and this
> is the only thing that gives me concern.
> I don't think sorting WBC's from whole blood was the original
> topic, but some replies were directed to sorting, and comparison of
> MoFlo to other high-speed sorting systems. As we are all aware that we
> need to keep the commercial content of this forum to a minimum, I only
> want to comment that information about instrument performance should
> not be distributed here, especially without hard documentation. A
> poster on standardized
> flow cytometric testing ("FLOWBENCH") will be presented at ISAC that
> addresses this topic. In the meantime, I would be happy to discuss the
> documented performance of MoFlo in comparison to other systems
> off-line.
>
> Peter
>
> Peter A. Lopez 970.226.2200
> Cytomation,Inc. 400 E. Horsetooth Rd. Ft.
> Collins,CO USA
> Manager, Applications Laboratory PeterL@cytomation.com
>
> ----------
> From: Joseph Trotter[SMTP:trotter@scripps.edu]
> Sent: Monday, October 20, 1997 3:49 PM
> To: Cytometry Mailing List
> Subject: Staining of Whole Blood.
>
>
> Bob Ashcroft replies to Jill Martin's question about analyzing WBC
> markers
> in unlysed whole blood as follows:
>
> >Basically, you need to run at high flow rates, of >50,000 cells/s and
> then
> >you need to threshold out most RBCs (say 90%, when 0.1% are WBCs),
> but the
> >remainder comprise WBCs at or below 1/1000 cells. Every white cell
> has 1, 2
> >, 3, 4,.. RBCs coincident except for a MoFlo MLS system with 5
> microsecond
> >dead-times, where you get mainly none, one or two coincident RBCs.
> >
> >My patent protocols generally use a pulse width and a DNA dye to add
> an
> >exclusion gate for non-nucleated cells, but then you must resolve the
> issue
> >of RBC coincidences and how they affect gates for the WBC subsets and
> the
> >dispersion in fluorescences of positives and negatives!
> >
> >If you don't have a MoFlo, then buy one; else forget it!
> >
>
> FYI,
>
> MoFlo is *not* the only commercial sysytem that is high speed with a
> deadtime
> adjustable down to approx. 5 microseconds. We often run with high
> throughputs on a
> BDIS Vantage + TurboSort using deadtimes at ~ 5 microseconds.
> I believe the losses, etc., of the MoFlo are very similar to the
> modified Vantage
> equipped with the TurboSort option. So.... I don't think we'll forget
> it.
> We have also used benchtop instruments (FACScan, FACS Calibur, etc.)
> triggering on
> CD3 immunofluorescence (as Howard described) with good results.
>
> Joe Trotter
> The Scripps Research Institute
>
>
>
>
>
>
> JT
>
>
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