[Cytometry] Problem with BD CS&T laser settings

Christopher Bare flowmail at verizon.net
Mon Jul 20 15:18:35 EDT 2009


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(out-of-date, invalid) values EVEN IF the user does NOT have permissions as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




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