Help with qunatification question for Image J

[Sarah Gallagher]

Dear List,

I would appreciate it if someone could give me help in the following  
matter.  I am attempting to use the program ImageJ to quantify the  
relative intensities of bands in a SDS-PAGE gel.  Specifically, I am  
trying to use the program to determine the ratio between three  
fluorescent bands in a single lane.  I am not interested in  
determining the absolute amounts, just in determining the percent  
ratio.  However, I would like the ratios to be determined accurately.  
I read in the instructions about the need to calibrate, but I'm not  
sure if this applies to this particular type of calculation?  Any  
input is greatly appreciated.

Best,
Sarah Gallagher



-------------------------------

Sarah S. Gallagher
Department of Chemistry
Columbia University
3000 Broadway, MC 3153
New York, NY  10027
[hidden email]

[Matt Twiddy]

Hi there,

I am wondering whether anyone knows of a plugin that can check the angle between two or more reference lines on an x-ray that might not intersect on the image that is being analyzed. I am trying to set up an experiment to test orthopedic surgeons pre-operative measurements of a lower limb radiograph prior to knee surgery and need something beyond the basic angle function provided by the toolbar angle function. Any help would be greatly appreciated. Thanks,

 

Matt Twiddy

_________________________________________________________________
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http://go.microsoft.com/?linkid=9655582

[Wolfgang Schechinger]

Dear Sarah,

I assume that you are using a fluorescence system like Licor-Odyssey.

Somehow you need to make sure which area under the curve corresponds to which amount of material. If you assume a linear relationship between signal intensity and sample amount, then double area under the curve means double amount of sample. As this might not be true, you need a standard curve for each band.

The easiest way to check this relation is to run a series of sample dilutions on the gel and to calculate a relative standard curve by plotting intensity vs dilution.

HTH

Wo



-------- Original-Nachricht --------
> Datum: Tue, 5 May 2009 17:58:44 -0400
> Von: Sarah Gallagher <[hidden email]>
> An: [hidden email]
> Betreff: Help with qunatification question for Image J

> Dear List,
>
> I would appreciate it if someone could give me help in the following  
> matter.  I am attempting to use the program ImageJ to quantify the  
> relative intensities of bands in a SDS-PAGE gel.  Specifically, I am  
> trying to use the program to determine the ratio between three  
> fluorescent bands in a single lane.  I am not interested in  
> determining the absolute amounts, just in determining the percent  
> ratio.  However, I would like the ratios to be determined accurately.  
> I read in the instructions about the need to calibrate, but I'm not  
> sure if this applies to this particular type of calculation?  Any  
> input is greatly appreciated.
>
> Best,
> Sarah Gallagher
>
>
>
> -------------------------------
>
> Sarah S. Gallagher
> Department of Chemistry
> Columbia University
> 3000 Broadway, MC 3153
> New York, NY  10027
> [hidden email]

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--
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[David Webster]

Matt,

Is this something that you can do interactively? If so, try using the
straightline tool on each line, and  reading out the line's angle from the
status bar. Then just subtract the angles by hand.

David

On Tue, May 5, 2009 at 3:31 PM, Matt Twiddy <[hidden email]> wrote:

> Hi there,
>
> I am wondering whether anyone knows of a plugin that can check the angle
> between two or more reference lines on an x-ray that might not intersect on
> the image that is being analyzed. I am trying to set up an experiment to
> test orthopedic surgeons pre-operative measurements of a lower limb
> radiograph prior to knee surgery and need something beyond the basic angle
> function provided by the toolbar angle function. Any help would be greatly
> appreciated. Thanks,
>
>
>
> Matt Twiddy
>
> _________________________________________________________________
> Internet explorer 8 lets you browse the web faster.
> http://go.microsoft.com/?linkid=9655582