Re: Quantification problem: more values despite weaker band?

Posted by Joel Sheffield on Apr 28, 2014; 5:03pm
URL: http://imagej.273.s1.nabble.com/Quantification-problem-more-values-despite-weaker-band-tp5007430p5007474.html

Hi Rena,

This protocol has some serious errors in it.  However, the most glaring is
that the scanning is done on a "conventional flatbed scanner".  You might
be aware that the light in a scanner will actually pass through your
intermediate bands twice--once as it leaves the light source, and again
when it is reflected from the back side of the scanner.  As a result, your
readings might not be particularly quantitative.  Some scanners have
specific modes for transmission.  It's much better to use one of those, or
even a carefully done photograph.  In all cases, I would suggest that you
carry out a true calibration of bands to ensure that you are getting linear
results.

Joel






Joel B. Sheffield, Ph.D
Department of Biology
Temple University
Philadelphia, PA 19122
Voice: 215 204 8839
e-mail: [hidden email]
URL:  http://astro.temple.edu/~jbs


On Mon, Apr 28, 2014 at 9:40 AM, Rena2014 <[hidden email]>wrote:

> Hi,
>
> Thanks already for your comments on my quantification problem!
> So far I followed a protocol from the University of Missouri
> (
> http://support.dalton.missouri.edu/index.php/wiki/Public:Quantifying_Color_Intensity/
> ).
> As recommended, I checked the "true intensities" and in some of my images I
> see high values for the black bands and low values for the white background
> (if the image is not inverted). So, clearly here is something inverted,
> right?
>
>
>
> --
> View this message in context:
> http://imagej.1557.x6.nabble.com/Quantification-problem-more-values-despite-weaker-band-tp5007430p5007470.html
> Sent from the ImageJ mailing list archive at Nabble.com.
>
> --
> ImageJ mailing list: http://imagej.nih.gov/ij/list.html
>

--
ImageJ mailing list: http://imagej.nih.gov/ij/list.html