UVP Life Science - Manual (Page 128)

LS Software User Guide
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• A new screen appears Step 2: Calibrate MW standard.
• In the Step 2 screen, the weights can be adjusted to match the bands that actually appear.
Complete instructions for this appear below-see Stretch Factor.
• Click OK to save the calibration.
Stretch Factor
The stretch factor establishes a mathematical relationship between the weights to describe their relative
movement. The larger the stretch factor, the more the lighter weights move in relationship to heavier
ones. The smaller the stretch factor, the less the lighter weights move. A stretch factor of 1.0 indicates
linear movement (weights move in direct proportion to their relative weights).
To adjust the weights to match the bands, use the stretch factor as follows:
• In the Step 2 screen of the Molecular Weight tool, ensure that Proportional calibration mode is
selected.
• Drag a known weight up or down with the mouse until it matches the appropriate band.
Alternatively, select the weight with the mouse (or TAB key) and move the weight up and down
with the UP and DOWN arrows on the keyboard (this helps adjust the weight by small amounts).
When there is a match of the weight with the band, the line color changes from blue to yellow
(default colors).