Hi, All

we ask your comments on a problem we have when
doing vertical sections with our Bio-Rad MRC 1024 UV.
When we measure calcium using INDO-1 and we scan a
cell in, for example, 15 steps, then we always have a
difference in the two emission lines of 405 and 460 nm
with regard to the increase and decrease of intensity in
the course of the scan. The maximum intensity of the
“red” image may be at step #6 and the maximum
intensity of the “green” image at step #10, the difference
being at about 3 to 4 µm.
We had a Bio-Rad maintenance visit with alignment of
the UV and 488 light path but the problem is not gone.
The intensity, of course, is of great importance as the
ratio 405 nm / 460 nm is the base for calculating calcium
concentration.
We would like to hear from anyone who has had any
similar experience or can comment this observation.
Thank you.

Hubertus Hipke


Dr. Hubertus Hipke
Institut für Tierphysiologie
Wartweg 95
35392 Giessen (Germany)
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