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You should be able to use linear gain without losing your unstained control
if you use the linear gain control to prescale the signal. Try setting up
on your control sample with the gain set to max (9.99 for facscan, 16 for
FACStar/ Vantage), and then drop it to unity for your experimentals, this
should give you at least as much range as the four decade log amplifier,
all you then need do is divide your control reading by the amplification
factor to get the readings on the same scale.
I'd advocate using linear since the quantization errors on log scale become
pretty big at the far end, both amplification systems are prone to
non-linearity.
Ray
At 12:24 pm 16/9/96, Alice L. Givan wrote:
>Hello Flowers,
>Could I initiate a controversy on how people would look at very small changes
>in fluorescence intensity between cells grown under different conditions? The
>problem is complicated by the fact that the stained cells in question are much
>brighter than the unstained controls, but stained cells (under different
>growth conditions) are only slightly different from each other. How would you
>set up the cytometer? Would you forget about the unstained controls? Would
>you use log or lin amplification? What system would give the *greatest
>sensitivity* taking all things into consideration?
>Thanks.
>Alice Givan
>Englert Cell Analysis Laboratory
>Dartmouth Medical School
>Lebanon, NH 03756 USA
Ray Hicks
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