Thermo Scientific Invitrogen Countess II FL, Руководство пользователя

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Problem Possible solutions
Getting incorrect concentration for the Countess ™ test
beads
• 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.
Variable counts for the same sample of cells
• If you are pipetting different samples from the same
cell sample, the variability could be due to pipetting
or mixing.
• Use recently calibrated pipettors and make sure that
the cells are well suspended by pipetting up and
down several times before adding trypan blue.
• Pipet the bead and trypan blue mixture up and down
several times to make sure it is well mixed, and load
10 µL into the slide without delay.
Variable counts when performing replicate counts of the
same slide
• If you are counting replicates of the exact same
slide, visually inspect that all cells are counted
correctly in the image.
• There may be a slightly different field of view each
time a slide is inserted. Depending on the
concentration and uniformity of the cells, this will
cause some variability when performing replicate
counts of the same slide, although it should be less
than 10%.
• When counting fewer cells, a small field of view
change for only a small number of cells can have a
larger affect. Count cells at a higher concentration to
reduce variability.
• Make sure that you do not shake or agitate the slide
between counts.
Appendix A Troubleshooting
Set nominal focus
A
Countess
™
II FL automated cell counter User Guide 61