Bio-Rad Image Lab™ Software - Manual (Page 165)

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User Guide | 165
The calibration curve displays. Standards are represented by green triangles.
Unknown values are represented by red triangles.
Note: Selecting the Force Through Origin checkbox always starts the
standard curve graph at 0,0, regardless of the best curve fit.
Note: Clicking the Standard Curve table generates a crosshair tool that
displays the numerical values associated with the placement of the cursor
in the graph.