Why alignment is important

Alignment makes it possible to accurately compare images by removing the positional variation introduced during the electrophoresis process. This is done at the pixel level to give the accuracy needed for fast, statistically robust, analysis.

Once alignment has been performed, each image in the experiment will be perfectly aligned so that a spot on image A will be in the same location as the matching spot on image B.

Alignment is the most important part of the SameSpots workflow, so any inaccuracies at this stage should be corrected before moving on to spot detection. The alignment views are designed to make finding and fixing any alignment problems as easy as possible.

The screenshot below shows two images being aligned. The images are overlaid on top of each other, one displayed in green and one in purple. When the images are not yet aligned (shown on the left), the separate spots are clearly visible. After alignment (shown on the right), the purple and green from each image combines to make black.

Overlay before alignment

Overlay after alignment

See Also: How do I align my gels?