UVP Life Science - Manual (Page 129)

Perform 1D Analysis
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• Adjust the stretch factor (scaling) between weights until the other weights match their appropriate
bands. Adjust it using the mouse wheel (rolling up increases the value, rolling down decreases it),
or enter a new value into the text box and click Set.
• Click OK to save the calibration.
Note: Using the Stretch Factor gives a weight match on the band up to 0.5% of the assigned
weight. To obtain exact placement on the band, use the manual mode, described in the
Using Manual Placement of Weights below.
Manual Placement of Weights
Instead of using the Stretch Factor, the weights can be adjusted individually using manual mode:
• In the Step 2 screen of the Molecular Weight tool, select Independent calibration mode.
• Move each weight separately, with either the mouse or the keyboard arrows, to position them
exactly on the band. Weights cannot pass one another, so it is usually best to start with either the
lightest or heaviest weight and work toward the other end. When there is a match of the weight
with the band, the line color changes from blue to yellow (default colors).
• Click OK to save the calibration.
Exact Placement of Bands
In the Independent calibration mode, as soon as the weight is exactly on the band, the color of the line
changes from blue to yellow (default colors). This means exact placement is achieved-- the weight will be
exactly on the band peak. Exact placement only occurs when the color changes from unmatched to
matched; further movement of the weight may alter the exact positioning. When in doubt, move the
weight completely away from the band and reposition it with the arrow keys until the color changes.
The
Independent > Tag All button reduces some manual work by aligning the weights of the ladder
starting with first band in the lane. Stretch factor is not taken into account &endash; only simple matching
is done.
Note: After calibration of two or more lanes, Retardation factor lines will be automatically calculated and
will replace any previous Rf line work.
Note: On the second window of the calibration operation (where users adjust weights to bands), the
colors of both the unmatched and the matched lines can be changed by using the controls in the
upper right corner.
Related Topics
• Molecular Weight Calibration