Agilent Technologies 4150 TapeStation system - Page 208

208 Agilent 4150 TapeStation System Manual
10 Troubleshooting
Troubleshooting RNA Applications
Slanted or smeared
bands
A bubble could be
located at the top of the
ScreenTape device
A bubble in the buffer
chamber distorts the
initial entry of a sample
into the gel
Always flick the ScreenTape device before
placing into the TapeStation instrument. See
“ScreenTape Devices” on page 87
Sample not collected at
the bottom of the vial
Insufficient volume
pipetted by the robotics
and applied to the lane
may affect the
migration behavior and
alter the band shape
Make sure to collect all liquid at the bottom of
the vial by centrifugation. See “Centrifugation
Recommendations” on page 97. Ensure that
after removing strip caps and inserting the tube
strips or 96-well sample plate into the
TapeStation instrument liquid is still located at
the bottom of the well and is not spilled
The sample may not
have been mixed
correctly with the
sample buffer
Ionic strength of the
sample/buffer mix may
not reach expected
optimal conditions and
thus electrophoresis is
impaired
Please follow the mixing recommendations for
the assay. See “Mixing Recommendations” on
page 94 for more details
The sample and sample
buffer may have started
to evaporate
Ionic strength of the
sample/buffer mix may
exceed the maximum
buffer strength due to
water loss and thus
electrophoresis is
impaired
Always ensure that samples are run on the
TapeStation instrument immediately after
preparation with sample buffer
A bubble could be
located within the gel
matrix
A bubble in the gel
matrix will introduce
significant artifacts in
the data. Those bubbles
cannot be flicked away
Always inspect ScreenTape devices for bubbles
in the lanes. Lanes in question cannot be used
for analysis. Such bubbles can form after the
expiration date or upon wrong storage. See the
Agilent Information Center and “ScreenTape
Devices” on page 87 for more information
The markers have
appeared in the sample
lane, but the sample
has not
The sample analyzed is
too diluted
The sample
concentration is below
the limit of detection
Concentrate your sample until it is within the
recommended range for the application (see
“Quantitative range” on page 107); then prepare
a new run. Use the High Sensitivity assay if
applicable
Insufficient Mixing Buffer and sample were
not sufficiently
vortexed. The dye could
not incorporate
completely into the
sample
See “Mixing Recommendations” on page 94
and the Agilent Information Center for more
information
Table 16 RNA - Possible causes of unexpected migration profile.
Problem Likely Cause Explanation Solution