Planar Chromatography
Planar Chromatography
In biochemistry, large molecules (like proteins or DNA fragments) are frequently separated by gel chromatography. Since they are usually invisible, one needs to stain them. One row in the picture represents the stained separated fragments of a large molecule. The more intense the color, the higher the concentration found at that spot. This Demonstration shows the variation in intensity in a chromatogram.
After color inverting the original chromatogram, we count black pixels and thus determine how much of the substance is located at each rectangular area on the film. By using the sliders, you can specify your area of interest. On the left the whole image is shown, whereas on the right your selection is magnified and centered. The percentage refers to the selected fraction of black pixels in that region. The slider for lets you rotate both images and the slider for lets you control the counting tolerance.
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