Bio-Rad Quantity One 1-D Analysis Software - Manual (Page 123)

Quantity One User Guide
5-6
Select No next to the Normalize prompt to apply the band detection parameters in the
same way to every lane in the gel image. Select Yes to normalize for the intensity of
the lane.
Shadow Rejection
“Shadow bands” are common gel artifacts. Shadow bands are spaced at tandem repeat
intervals and decrease in intensity as they progress further from a real band. The
Shadows parameter is designed to limit the detection of shadow bands (see also Band
Limit).
Select Reject to turn on the shadows filter. A band will detected only if it is darker
than the one above it or spaced further than one tandem repeat unit from the previous
band. This greatly reduces the number of shadows identified as real bands.
Select Accept to turn off the shadows filter.
Band Limit
If you know that all the lanes in a gel contain a specific number of bands, you can
click on the Limit button next to the Bands prompt and type in the number of bands
that you know are present. Only that number of bands will be detected in each lane,
reducing the need for later editing.
Sensitivity
The Sensitivity setting determines the minimum signal intensity in the image that will
be defined as a band. The higher the sensitivity value, the more bands will be
detected.
If the sensitivity is set too high, background noise may be detected as bands. If the
setting is too low, real bands may be missed.
The default sensitivity setting is 10.00. If the gel has faint bands (e.g., O.D. < 0.05,
counts < 2,000), you may want to increase this value to 20.00.