Troubleshooting
Observation
Possible cause
Recommended action
Abnormally high percentage of
dead cells or live cells counted
as dead
Focus was not correct for the
sample.
Ensure that the cells are focused correctly so
that live cells have bright centers and dead
cells are dark throughout. If the cells are not
well focused and look dark on the screen, the
Countess
™
3 FL cell counter will count them as
dead cells.
Live cells vs dead cells were
difficult to distinguish.
If cells are well focused, have bright centers, and
are being counted as dead, confirm that they
are within the appropriate cell size range and try
adjusting the settings.
Cells were exposed to trypan
blue for too long.
If cells are exposed to trypan blue for a long
period of time, viability could be affected so slide
should be prepared and counted fresh each
time for best results.
Capture settings were not
optimal.
Gate out the debris using the size, brightness,
and circularity sliders.
Autofocus does not focus
properly
Debris or other material
interfered with the focus.
Make sure there are no bubbles or debris visible
on the screen that could interfere with the
autofocus and make it more difficult to get the
sample in the correct focal plane.
Live cells vs dead cells were
difficult to distinguish.
If cells are well focused, have bright centers, and
are being counted as dead, confirm that they
are within the appropriate cell size range and try
adjusting the settings.
Incorrect concentration for the
Countess
™
test beads
Beads were not suspended in
solution or mixed correctly.
The beads can settle quickly in solution, which
will affect the concentration reading.
Vortex the bead stock on high for a full 30
seconds to resuspend, and add 10 µL of the
bead suspension to 10 µL of trypan blue without
delay.
Pipet the bead and trypan blue mixture up and
down several times to make sure it is well mixed
and immediately load 10 µL into the slide.
A
42
Countess
™
3 Automated Cell Counter User Guide
Содержание Invitrogen AMQAX2000
Страница 55: ......
