Regenerate Array error workaround.

Phillip San Miguel pmiguel at purdue.edu
Mon Mar 20 12:02:55 EST 2000


    If you get the error "FMCuvetteBlock Object: Unable to
Attain Pressure from 8 Syringes of Fluid" during a normal
run, it probably means something very bad (like a cracked
cuvette) has occurred[1]. But if you get this error during
some procedures, it may be a trivial problem that requires
no intervention by a Field Service Engineer. Here is an
example:
    I've got a 'weak' sheath flow pump. Although it rarely
crashes during a normal run, it has crashed both times I've
tried to use the Regenerate Array Wizard from Data
Collection v. 1.1.
    To understand this story, one should realize that the
new (v 1.1) Regenerate Array Wizard has 2 main parts. During
the first part (which is supposed to take about 70 minutes)
polymer is rinsed from the tubing, front and rear blocks and
the capillaries. The second part actually uses the nitric
acid to clean the array and then puts polymer back in
capillaries, etc. For reason that escape me the Wizard
instructs the user to remove the shringe filter during the
first part and then put a new, dry one in before the second
part. I don't think my weak Sheath Flow Pump can handle
pushing stuff though this dry filter--so it errors out here.

    When I restarted the wizard it can't get past the step
where it presurizes the cuvette to 80 PSI and finally errors
out with the message "FMCuvetteBlock Object: Unable to
Attain Pressure from 8 Syringes of Fluid" But the cuvette
won't pressuries past about 7 PSI with water in the
capillaries. The water just isn't viscous enough to provide
more back-pressure than this. So no matter how many times
one runs the Wizard it will error out at this point. Nothing
is wrong--but once there is water in the capillaries this
Wizard will not function. The only reason the wizard
attempts to pressurize the cuvette to 80 PSI is to force
polymer from the capillaries and replace it with water
before doing the acid step. Since my array had no polymer
left in it, the solution was to run "install array" instead
of "regenerate array." My field service engineer had me run
install array from service tools, but the wizard in data
collection would probably work also. Install array begins
with the acid wash then does a water to polymer switch
(after rinsing away all the acid.)  Note that you don't want
to do this if there is still polymer in your array!
    In the future I think I will be able to avoid the entire
problem by not putting any filter in during the regenerate
array procedure. Then I'll run the change polymer wizard to
install a new filter.

Phillip San Miguel
Purdue University Genomics Core Facility

[1] A great resource on the web is:
http://genome.wustl.edu/gsc/TechHelp/3700help/trouble.htm
WashU has screenshots and diagnoses of various troubles that
can occur with the 3700.

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