Re: widefield autofluorescence in unlabeled cells - a filter mystery?

Posted by Z.J. Zhang on
URL: http://confocal-microscopy-list.275.s1.nabble.com/widefield-autofluorescence-in-unlabeled-cells-a-filter-mystery-tp7592150p7592156.html

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Doug,

Your guess is likely correct.
I used to have a similar system. It is not hard to take the filter wheel off. You can then check the excitation filters and you will likely see physical damages ('turns') on the filter even  with naked eyes. If budget allows, it might be a good idea to change the light source as well.

Zhaojie Zhang
Director, Jenkins Microscopy Facility
University of Wyoming

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Subject: widefield autofluorescence in unlabeled cells - a filter mystery?

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A colleague asked me to take a look at their widefield microscope. It is an inverted microscope with a 100W Hg source, excitation filter wheel, a couple of choices for dichroics in the microscope filter changer and a filter wheel in front of the camera. They are seeing unlabeled cells fluoresce green (FITC/GFP set) with an otherwise black background where there are no cells. The microscope is approximately 15 years old.

My guess is that the excitation filters have failed (or are failing) after being on the receiving end of a 100W Hg lamp for all this time. Any other thoughts?

Doug

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