chemiluminescent detection

Paul N Hengen pnh at fcs260c2.ncifcrf.gov
Tue Nov 22 14:21:42 EST 1994


 In article <3asvbu$7th at mserv1.dl.ac.uk>
 Sasha Kraev <bckraev at aeolus.ethz.ch> writes:

> Paul, your question really puzzles me. The very first paper on the use of
> chemiluminescence does describe the use of a Polaroid film for detection.
> Why shouldn't a BW paper be the same? The real problem is, what are you going
> to achieve using it? Is it because you think it is cheaper? In fact, a high 
> speed negative film (e.g.Kodak T-max 1600 ISO) should be even better, but it 
> is very unconvenient to develop it in total darkness. I never thought of 
> using anything but the X-ray film, because it is developed in a processor, 
> while an Ilford paper probably wouldn't be processed properly (in an X-ray 
> film processor).
> Did I understand your problem correctly?
> Have a nice day.
> Sasha
>
> P.S: A new Kodak Bio-Max (single sided) film is wonderful for the purpose!

It's not really a problem I'm having. It's more a matter of convenience.  I
just happen to have a box of B&W paper and wanted to see if others had tried
it. As I understand it, polaroid film development cannot be stopped during the
processing. I was thinking that I could expose the paper by direct contact with
the membrane, and develop it by hand in the darkroom. I think this would work
because the kit I bought from Tropix uses a substrate (CSPD) which produces
light at a maximum of 477 nm wavelength, ie. in the visible blue range. Since
the B&W film is not sensitive to red light (650-700 nm), but is sensitive to
blue light, I could develop the paper under red light in a tray and stop the
development when I see the best image, rather than simply feeding the X-ray
development machine...and then going back to the exposure step to tweak the
exposure time. In addition, some X-ray films have the emulsion on blue plastic
which creates a grey background if it were to be re-photographed for a
publishable figure. The only advantages I see with using X-ray film are 1.)
people are used to dealing with it 2.) they are clear and have emulsion on both
sides so that you can amplify the light with mirrors or Lightning screens for
radioisotopes, and 3.) X-ray film is quite fast with speeds of approximately
3500 ASA, reducing the time needed for exposure.

Have you tried the Kodak Bio-Max? Is it a white paper or clear plastic film?

*******************************************************************************
* Paul N. Hengen, Ph.D.                           /--------------------------/*
* National Cancer Institute                       |Internet: pnh at ncifcrf.gov |*
* Laboratory of Mathematical Biology              |   Phone: (301) 846-5581  |*
* Frederick Cancer Research and Development Center|     FAX: (301) 846-5598  |*
* Frederick, Maryland 21702-1201 USA              /--------------------------/*
* - - -  Methods FAQ list -> http://www.ncifcrf.gov:2001/~pnh/info.html - - - *
*******************************************************************************



More information about the Methods mailing list