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Emission wavelength of EtBr/DNA for a CCD camera filter

Karl Voss karl at hobbes.chem.ualberta.ca
Mon Feb 3 18:54:12 EST 1997

Dr. Duncan Clark (duncan at genesys.demon.co.uk) wrote:
> Hi Folks,

> Following the odd accident over the last few months the glass bandpass
> filter I use in front of a CCD camera now has a few cracks etc. My
> original was 600nm +/- 70nm which was wide enough (given the that CCD
> chip can see from UV to IR) to let through the infra-red from the UV
> tubes as well as the EtBr emission at 590nm. This meant I had to be
> careful about using max sensitivity on the camera. So what are people
> using out there? Can I go for a say a 590nm centre frequency filter with
> only a 10nm bandpass or is that too narrow. I want something inexpensive
> and off the shelf. I can get that sort of filter from Edmund Scientific
> or I think Corian.


You can certainly use a small bandpass filter for EB fluorescence, but you
will suffer from some loss in sensitivity.  The 70nm bandpass that you are
using seems much too wide; you do not want any overlap with you excitation
filter.  I think that we are using a 605DF35 from Omega optical for 
emmission filter and a 535DF25 for excitation from a mercury bulb in our 
fluorimeter for EB.  I can check again if you are interested.  

Anyway I guess which filter you pick depends on the application but I would
likely use something like a 605DF40 filter (605nm +/- 20nm).

Good luck



If it ain't broke it doesn't have enough
features yet

Karl Voss
Department of Chemistry
University of Alberta
Edmonton, Alberta, Canada
T6G 2G2

karl.voss at ualberta.ca
phone 403-492-0222
fax   403-492-8231

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