Flourescent fading GFP
Eric Robb Siegel
esiegel at UNIX1.SNCC.LSU.EDU
Sun Aug 18 18:13:43 EST 1996
On 17 Aug 1996, claude selitrennikoff wrote:
> Has anyone ever observed GFP bleaching in certain organisms?
> I am expressing GFP in a fungus and I have noticed that the GFP is
> fading under extended UV exposure. This occurs very quickly when I put
> on a microscope slide, which I presume is due to lack of oxygen.
> However, it occurs more slowly when I leave the microscope slide off.
> As far as I can tell, the bleaching is irreversible.
> My guess is that the chromophore formation is slightly altered in this
> fungus, and the result is a lower stability.
> Any suggestions?
> Dr. S. Canada
While I don't know if GFP is known for photobleaching, I do know that
most fluorescent dyes used in epifluorescence microscopy are subject to
photobleaching. I have found that putting sodium azide in my samples
makes them take longer to photobleach. I am told that N-ethyl maleimide
also protects against photobleaching. However, both are toxic to the
cells. I believe that Molecular Probes, Inc. sells non-toxic anti-fade
reagents, but I doubt if they are cheap.
P.S.: While writing this, I was struck by the question, Has anyone ever
tried sodium ascorbate an an anti-photobleaching reagent for
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