Re: fluorescence intensity

Posted by Joel Sheffield on Sep 24, 2007; 3:10pm
URL: http://imagej.273.s1.nabble.com/fluorescence-intensity-tp3698342p3698344.html

I would emphasize Michael's point about the range of intensity.  You
must make sure that your brightest image is within the 0-255 range of
the 8-bit image (for example).  You will not be able to compare two
images each of which is so bright that it exceeds that limit.

Joel

Date sent:       Mon, 24 Sep 2007 11:54:13 +0200
Send reply to:   [hidden email]
From:           Michael Weber <[hidden email]>
Subject:         Re: fluorescence intensity
To:             [hidden email]

> Hi Anette,
>
> the are a couple of ways to measure intensity. The most simple way is to
> load an image, point the mouse to the pixel of interest and check the
> signal intensity in the main tool bar. This could be a first test if the
> images where acquired in the range of the detector (=if nothing it
> overexposed). Did you acquire all images under the same condition
> (excitation power, filter setup, exposure time)? Otherwise it will be
> tricky to compare them.
>
> You can also measure regions by drawing i.e. a circle in the cell and go
> for "Analyze" > "Measurements". There are also plugins/macros to automate
> this, but a couple of manual steps before are probably go to find the best
> way.
>
> cheers,
> Michael
>
>
> > Dear ImageJ,
> > I have a question how to use the ImageJ program. I have labeled cells with
> > a fluorescence dye. I let the cells in culture about several days. Than I
> > made pictures with the fluorescence microscope on day 1, 3 and 5 after
> > staining. Now I want to messure and compare the fluorescence intensity
> > signal over these days and furthermore I want to examine whether there is
> > any weakening.
> > So, can you say me how to to this with the ImageJ program?
> >
> > Thank you.
> >
> > With kind regards,
> > Anette Christ

--
Joel B. Sheffield, Ph.D.
Biology Department, Temple University
1900 North 12th Street
Philadelphia, PA 19122
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