FITC detection limit for a normal fluorescent microscope, NOT A CONFOCAL

Bob Ashcroft (cytomat@netcore.com.au)
Thu, 21 Aug 1997 11:01:38 +1000

My fresh batch of Quantum 24 beads have 6,000, 16,000, 37,000 and 90,000
MESF molecules respectively in the particle mixture. The fluorochrome is
FITC.

When I look at them on the fluorescent microscope, I can only see the ones
with 90,000 MESF.

Is this normal?

....If not, what is the limit for a dark-accomodated eye?
Yeah, allow for normal biological variation, by assuming I have 20+/20+
vision!

....If not, what do I do about it?

(I know fading is a problem, and have had useful suggestions on this
previously.
We want to use a high sensitivity, 5 mLux, camera to quantify fluorescence)

Thanks,
Bob