Bio-Rad Microplate Manager Software - Manual (Page 44)

Analyzing Data Using a Standard Curve
36
Log/log Fit
The Log/Log curve fit option fits the best straight line to the data consisting of the
logarithm of the OD (response) vs. the logarithm of the concentration.
For the Log/log method, the equation for the standard curve is:
Log
10
(y) =Intercept + Slope*Log
10
(conc)
In the plot, the concentration and the OD axes are displayed on the log scale. The
calculated intercept, slope, the correlation coefficient (r) and the chi
2 values of the
standard curve are shown below the plot.
The log-log option should be used when a linear plot of the data exhibits a strong
curvature up or down.
Quadratic
The quadratic function fits the best parabolic curve according to the equation
Y = A + Bx + Cx 2
where A is the intercept, B is the slope of the curve at the intercept, and C is the
measure of curvature of the parabola.
The quadratic fit is most appropriate when the standard curve curves up or down.