Bio-Rad EXQuest Spot Cutter - Manual (Page 133)

PDQuest User Guide
4-12
4.3 Filtered and Gaussian Images
When spots are detected in PDQuest, the original gel scan is filtered and smoothed to
clarify the spots, then three-dimensional Gaussian spots are created from the clarified
spots. The end result is three separate images: the original Raw 2-D scan, which
remains unchanged; the Filtered image, which is a copy of the original scan that has
been filtered and processed; and the Gaussian image, which is a synthetic image
containing the Gaussian spots.
Fig. 4-6. Images created during spot detection.
All quantitation and other analysis are performed on the Gaussian image. PDQuest
preserves all three images so that at any point you can go back and reexamine the
original scan and the Filtered image to compare the original spots with the synthetic
spots in the Gaussian image.
Note: Any spots not detected in the Filtered image will not be included in the Gaussian
image. You can add spots to the Gaussian image during spot editing, as described
in following sections.
A Raw 2-D Scan, Filtered image, and Gaussian image of the same gel are part of the
same scanset; they all share the same root file name with different extensions.
Therefore, performing spot detection on an original Raw 2-D scan named
Proteins.gsc would result in a Filtered image named Proteins.gim and a Gaussian
image named Proteins.gsp
After spot detection, the Raw 2-D scan, Filtered image, and Gaussian image will be
displayed in subwindows of the same window. The file name and type of each image
are displayed at the bottom of each subwindow.
Gel image
Raw 2-D
Scan
Gaussian
Image