Hi Joseph,
Well, I do not want to say that 45mW cannot work, although I have never
tried it with less than 100mW. I have used to different lasers 1 - a dye
laser tuned to 595nm which gave us probably about 140 - 200mW (large day to
day variation on the output depending on the age of the dye, alignment
etc). Currently I am using a spectrum laser tuned to give a 647nm line and
I know that if I can get 200mW the signal is significantly better than if I
use 150 or 130mW. This of course does not mean that less is not working,
just definitely not as good.
An important other point (apart from the filters) is the PMT. If you do buy
an additional PMT, it is crucial to buy a deep red sensitive one. That can
also make 20 - 100% difference, depending on the luck of the draw, i.e.
whether you get a "super" PMT or just a good one. If you already have one
on the APC channel you might also try and swap the two and see whether one
can give you better results.
Could you consider using Cy7-PE instead of Cy7-APC, or are you already
doing that? I personally found that color a bit better and less trouble.
Although it also performs much better at higher laser power, a lot of
people have quite a powerful argon laser anyway.
Nicole
Nicole Baumgarth
Center for Comparative Medicine
University of California
Davis, CA 95616
Tel: 530 - 754 5813 (office)
530 - 754 6538 (lab)
FAX: 530 - 752 7914
This archive was generated by hypermail 2b29 : Sun Jan 05 2003 - 19:01:28 EST