We have tested the Zeiss LED plate with hanging and sitting drop trays
and found it it unsuitable for looking at crystals. The reason is the
really low contrast with this kind of diffuse illumination. Obviously,
contrast is generated by refraction at crystal/mother liquor
interfaces and this effect diminishes with diffuse light coming from a
range of incidence angles.
Clemens
Zitat von Jürgen Bosch <jubo...@jhsph.edu>:
Here are some numbers
Matthew.Franklin:
Okay.
Start: 71.9 F
Finish: 73.1 F
Temperature measured with thermocouple Scotch-taped to the center of the
microscope stage, underneath an empty 96-well plate. Room thermostat set
to 70.
I should have mentioned that I was thinking about fiberoptics and
not the halogen light directly under the tray.
Still I always had the impression that there's a significant
temperature difference when using the fiberoptics for a long time
e.g when mounting crystals.
The microscope in question is a Zeiss and the $ difference between
LED & halogen is about 2.5K in favour of the LED system.
I have seen the LED version and it seemed good to me - but I have
not looked at crystal trays of course.
I'll post a summary in a few days.
Thanks for all your replies so far,
Jürgen
-
Jürgen Bosch
Johns Hopkins Bloomberg School of Public Health
Biochemistry and Molecular Biology, W8708
615 North Wolfe Street
Baltimore, MD 21205
Phone: +1-410-614-4742
Fax: +1-410-955-3655
