[Cytometry] Problem with BD CS&T laser settings

Christopher Bare flowmail at verizon.net
Tue Jul 21 14:46:45 EDT 2009


Felix,

You are welcome, and you are correct!

We run UltraRaindows in addition to CS&T by applying what BD calls
"Application Settings." This changes our voltages by an amount relevant to
the CS&T defined voltages to bring our beads back to the consistent channel.

Again, be warned that Application Settings will change your Area Scalings IF
when you set the Application Settings, your scalings are DIFFERENT from the
CS&T at that moment. (It's all about the DeltaFromCS&T). So again, be
careful defining the Settings.

Our best typical approach has been to instruct every user to "Use CS&T" but
"Duplicate Without Data" to preserve their PMT voltages. So far, that
sequence works.

Cheers!

-cbb

> -----Original Message-----
> From: Felix Heymann [mailto:felix.reichel at ukb.uni-bonn.de]
> Sent: Tuesday, July 21, 2009 12:35 PM
> To: Christopher Bare
> Cc: 'Cytometry List'
> Subject: Re: [Cytometry] Problem with BD CS&T laser settings
> 
> Hi Chris, hi all,
> thank you for this enlightening description, I think, it is very
> important that people doing flow on the BD machines know about these
> pitfalls, it can not be stressed enough that there is probably very
> little that can mess up your experiments more than wrong laser settings.
> Anyway, I still have my issues using the CS&T do do a full setup of my
> instrument, since (as I mentioned earlier) at least for me the CS&T
> settings tend to be total crap in terms of the PMT voltage settings and
> I normally have to readjust them anyway (big time!) before my actual
> measurement.
> 
> I actually reran the CS&Ts together with CaliBRITE and Rainbows on our
> Aria II for the configurations, doing a performance check first (which
> was ok), but when I actually ran the beads as a standard sample, quite a
> lot of PMTs were way out of line and set either too low (no good
> discrimination of dim and med CS&Ts) or too high (bright beads crammed
> to the highest channels). This is in fact a problem, since I can not
> teach the flow users here to rely on the CS&T settings, because they are
> utter nonsense in terms of the PMTs, although area scaling, laser delay
> and window extensions are adjusted accurately.
> 
> So what would be a good way to solve this issue? My idea so far would be
> to tell the people to stick to the 'use CS&T' in the dialogue when asked
> to have the delay etc adjusted right but disregard the PMT voltages and
> start with their single stains from scratch to adjust the PMTs? I have
> no other idea how to do it so far, so if you come up with a different
> solution, please let me know.
> 
> I really like the idea behind the CS&Ts, but either I am hopeless using
> them or there may be some room for improvement from BD side to narrow
> the gap between artifically labled, small and very bright beads compared
> to big unregularly shaped cells with highly variable fluorescence
> properties.
> 
> Best regards
> 
> Felix
> 
> Felix Heymann
> Scientific research fellow
> Medical clinic III, University hospital Aachen
> Germany
> 
> 
> > Flownauts!
> >
> > We at Rockefeller recently discovered a dramatic "feature" of the DiVa 6
> > software utilizing CS&T to set laser delay and area scaling when applied
in
> > a multi-account (multi-user with different logins) setting that can
cause
> > drastically wrong values to be applied. That, of course, can make your
> > parameters falsely negative for the entire octagon/trigon.
> >
> > The Problem:
> > When a user logs in, DiVa checks the database against the Current CS&T
> > values stored on disk. If there is a mismatch, the user is given a
Dialogue
> > Box asking to "Use CS&T" or "Keep Current." If the user clicks "Keep
> > Current," the instrument laser settings are changed to non-current
> > (out-of-date, invalid) values EVEN IF the user does NOT have permissions
as
> > assigned in the "Administration" window.
> >
> > The laser settings that the user previously used may be very very VERY
> > different from the current instrument configuration (say, if a new laser
was
> > added).
> >
> > A Solution?
> > If an account does not have permission to adjust delay and scaling, they
> > shouldn't get the Dialogue Box asking them to keep current! BD should
> > reprogram DiVa to ALWAYS apply Current CS&T settings for
non-permissioned
> > accounts.
> >
> > We have instructed our users to ALWAYS choose "Use CS&T," but not
everyone
> > listens, or understands. Failure can render subsequently acquired data
> > invalid and useless. And unlike compensation or airbubbles, this can not
be
> > retrospectively repaired.
> >
> > A fix is better than a workaround.
> >
> > I found this because a user complained that his CD3 APC was all a big
> > negative smear. I noticed his 640nm delay was 18 instead of 32. I
applied
> > Current CS&T and his positive population magically appeared.
> >
> > We run two self-service LSRII (one 4 laser, one now 5 laser). We define
a
> > single Instrument Configuration for all (200+) users with parameters
names
> > for laser source and PMT position (e.g. 488-B) in order to prevent any
> > conflicts for mismatched configs and avoid end-user mistakes. We deny
users
> > the ability to change delay and scaling, instead administratively run
CS&T
> > weekly and post the numbers on the machine for user confirmation. We do
not
> > allow users to run CS&T themselves, or create and use alternate
Instrument
> > Configurations. We recently upgraded one machine from 4 to 5 lasers, and
> > reordered their intercepts. This changed all delays (except 488).
> >
> > The way DiVa sets a user's laser delays and scalings:
> > If the user chooses "Keep Current," DiVa sets the values according to
the
> > Last Tube created by the user during the previous login. If the user
does
> > not have any tubes in the database, DiVa uses the user values from a
> > different user_account_laser_defaults table, which is set when the user
last
> > logged OUT. So if CS&T has been run since the user last logged in, there
> > will be a mismatch and the user gets the Dialogue Box.
> >
> > Sincerely,
> > Cris Bare
> > Rockefeller University
> > Flow Cytometry Resource Center
> >
> >
> > _______________________________________________
> > Cytometry mailing list
> > Cytometry at lists.purdue.edu
> > https://lists.purdue.edu/mailman/listinfo/cytometry
> >
> >



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