Bio-Rad EXQuest Spot Cutter - Manual (Page 134)

Detecting and Editing Spots
4-13
Fig. 4-7. Example of a Scanset.
Note: Use the Assign tool and Configure Subwindows command on the main toolbar to
arrange images in subwindows. See section 3.1, Windows and Subwindows for
more information about viewing commands.
What Are Gaussian Spots?
Fuzzy, streaked, or overlapping spots in a Raw 2-D gel can be difficult to accurately
quantify. Because the image profile of an ideal spot conforms to a Gaussian curve,
PDQuest uses Gaussian modeling to create “ideal” spots that can be easily identified
and quantitated.
A Gaussian spot is a precise three-dimensional representation of an original scanned
spot. Gaussian curves are fitted to the scanned spot in the X and Y dimensions, and
then additional modeling is performed to create the final Gaussian spot.
Using Gaussian modeling, you can accurately quantitate overlapping spots, spots in
gel streaks, and multiple spots in clusters.
Note that spots created using the spot boundary tools (section 4.6, Spot Boundary
Tools) are not Gaussian modeled, even though they appear in the Gaussian image.