X-ray excitation of fluorescent dyes

[Knecht, David]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

A colleague of mine heard a talk at a recent meeting in which a physician was treating cells or tissues with acridine orange and then bombarding with X-rays and the AO stained cells were killed, while the non-treated cells were not.  Their target was osteoclasts to try to prevent bone loss in cancer patients.  They seem to have no data on the mechanism, but two hypotheses jump to mind:
1.  The AO actually has an absorption/excitation spectrum which includes the wavelength of X-rays (0.01-10nm) and that absorption causes toxicity (free radicals?)
2.  The AO is doing something to the cells to make them more sensitive to X-rays (neutralizing endosomes and lysosomes) and it has nothing to do with light absorption by the dye.
My question is whether anyone knows if there is data on the behavior of fluorescent dyes like AO in this very short wavelength light spectrum.

Thanks- Dave
Dr. David Knecht
Professor , Department of Molecular and Cell Biology
University of Connecticut
91 N. Eagleville Rd.
U-3125
Storrs, CT 06269-3125
860-486-2200

[Tobias Baskin]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
Post images on http://www.imgur.com and include the link in your posting.
*****

Dave,
         Acridine orange intercalates into DNA. Perhaps that makes the
DNA absorb Xrays more readily?

Tobias

On 10/25/17 3:51 PM, Knecht, David wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> Post images on http://www.imgur.com and include the link in your posting.
> *****
>
> A colleague of mine heard a talk at a recent meeting in which a physician was treating cells or tissues with acridine orange and then bombarding with X-rays and the AO stained cells were killed, while the non-treated cells were not.  Their target was osteoclasts to try to prevent bone loss in cancer patients.  They seem to have no data on the mechanism, but two hypotheses jump to mind:
> 1.  The AO actually has an absorption/excitation spectrum which includes the wavelength of X-rays (0.01-10nm) and that absorption causes toxicity (free radicals?)
> 2.  The AO is doing something to the cells to make them more sensitive to X-rays (neutralizing endosomes and lysosomes) and it has nothing to do with light absorption by the dye.
> My question is whether anyone knows if there is data on the behavior of fluorescent dyes like AO in this very short wavelength light spectrum.
>
> Thanks- Dave
> Dr. David Knecht
> Professor , Department of Molecular and Cell Biology
> University of Connecticut
> 91 N. Eagleville Rd.
> U-3125
> Storrs, CT 06269-3125
> 860-486-2200
>

--
       __    ___   ^    ___   ___   Tobias I. Baskin
      /  \  /     / \  /      \      Professor
     /   / /     /   \ \       \      Biology Department
    / __/ /__   /___  \ \       \__    University of Mass.
   /     /     /       \ \       \      611 N. Pleasant St.
  /     /     /         \ \       \      Amherst, Massachusetts
/     /___  /           \ \___/   \_____ USA  01003    413-545-1533
   www.bio.umass.edu/biology/baskin                       BLOG: blogs.umass.edu/baskin/