Bio-Rad Microplate Manager Software - Manual (Page 73)

Chapter 5. Protocols
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To set absorbance limits, select the appropriate checkbox(es) and enter ODs in the
appropriate field(s).
If none of the limit checkboxes is selected, then all data points will be included in the
velocity calculations.
Velocity
There are two methods for calculating kinetic velocities. The first fits a line to the
entire data set and defines the reaction velocity as the slope of this line. The second
fits a line to every subsegment of n points, where n is specified by the user, and
identifies the greatest velocity from among these segments.
Under Kinetic Mode, select one of the following options:
•
Velocity. The kinetic velocity (slope of the absorbance versus time curve) will
be calculated by linear regression using all the data points. If time or absorbance
limits are selected, then all the data points within the selected range are used in
the velocity calculations.
•
Max. Velocity. Kinetic velocities will be calculated for overlapping segments of
the reaction, and the maximum velocity will be reported. You then select the
number of data points to include in each segment of the reaction; the minimum
number of points is two. The first segment begins with the first data point and
extends for the number of points you have selected. The second segment begins
with the second data point, the third segment with the third data point, etc.
For cases where the absorbances decrease with time, the velocities will be negative.
To change the sign of the velocities, select the Negative Kinetics checkbox.
½
If the velocities are negative, then the velocity or maximum velocity axis of the
Standard Curve Report is constrained to linear unless the Negative Kinetics
box is checked (logarithms cannot be taken of negative values).