256 | Chapter 5: Qualification
Troubleshoot as follows:
If the test fails once:
o
If the problem appears to be related to particular wells, clean those aspiration
tubes: remove the manifold and thoroughly clean the tubes with the stylus (
Clean the Dispense/Aspirate Tubes on page 202
test.
o
Failure of this test is commonly caused by improper aspiration tube placement
within the wells, usually because a microplate other than the recommended
Corning Costar
®
was used. If you must use a plate
other than
a Corning Costar,
modify the Aspirate Height, i.e., Z position, or horizontal X or Y position
parameters in a copy of the protocol to correct this error. After making this
change, retry the test using a new microplate.
If the test fails a second time: For 96-well plates, perform the
Evacuation Diagnostic
Test
. All other plate types, closely examine the residual volume in each well to
identify which aspirate tube(s) are clogged.
Evacuation Diagnostic Test
n
Conduct this test if the standard Evacuation Efficiency Test fails
twice
when
using a
96-well
plate. This test will confirm which aspirate tube(s) may be
clogged, or if the plate’s alignment or position is the problem. For a ll other
plate types, a close examination of the residual volume in each well will
identify which aspirate tube(s) are clogged.
1. If you have not already done so, repeat steps 2 through 7 of the standard
Evacuation Efficiency test, using
Solution #2
for the dispense fluid. Be sure to
recalculate the
Mean Residual Weight
.
2. Pipette
Solution #1
into each well, on top of the residual solution: up to 300
µL/well in a 96-well plate or 100 µL/well in a 384-well plate.
3. Shake the plate to achieve uniform distribution of the remaining dye in each
well.
4. Read the plate in an optical reader (blank on air), using the dual-wavelength
method (630 nm - 450 nm), then print or export the results.
5. Use the
Evacuation Efficiency Test Worksheet
to perform data reduction:
l
Calculate the sum of the OD values for all wells, then divide by
the number
of wells
to determine the
Mean OD
for the plate.
l
Divide the Mean OD by the
Mean Residual Weight
(from step 1), to find the
Residual Factor
.
MultiFlo™ FX Multi-Mode Dispenser
