24
Run Sample,
continued
Set gates and
thresholds,
continued
5.
To set the threshold for Annexin V fluorescence, touch the
Annexin V
thumbnail histogram.
The pop-up window displays the “# of cells vs. Fluorescence” histogram for
Annexin V fluorescence, the slider bar for adjusting the threshold for
fluorescence, and the buttons for displaying the Sample and/or the Control
fluorescence data in the graph.
6.
Touch
Sample fluorescence
and/or
Control fluorescence
to display the desired data. The buttons are filled to signify
that the appropriate data is displayed.
7.
Set the threshold by moving the
blue button
on the slider bar.
8.
Touch
Apply
to confirm and return to the previous screen. Only cells above the
threshold (i.e., to the right of the blue boundary line) are counted and the data is
updated with the new count.
To return to the previous screen without setting the threshold for cell size, touch
Close
.
9.
To set the threshold for PI, the remaining fluorescent channel, touch
PI
and
repeat the same procedure for PI.
Biological molecules found within cells fluoresce upon excitation and result in
background fluorescence. Because the Tali
™
Image-Based Cytometer is a highly
sensitive instrument, this background fluorescence is detected and displayed as a
peak closest to the 0 RFU (relative fluorescence unit) value. To eliminate the
background fluorescence from your calculations, adjust the threshold to exclude the
cells in this peak by moving the threshold to the right of the peak.
