Question 1

How do you calculate Vmax from a kinetic assay?

Accepted Answer

Take the steepest linear segment of the blank-corrected signal-versus-time curve and report its slope (signal units per minute). Labreador scans a sliding window over the time course to find the maximum slope automatically at labreador.com/group-comparison.

Question 2

How is AUC calculated for a time course?

Accepted Answer

By the trapezoidal rule: sum over consecutive time points of (y_i + y_{i+1}) / 2 x (t_{i+1} - t_i), using blank-corrected values.

Question 3

Should I subtract the blank or the negative control?

Accepted Answer

Subtract the blank to remove instrument and reagent background — that is a technical correction. The negative control is a biological baseline used for normalisation or as the comparison group in the statistics, not for subtraction.

Question 4

When should I use Mann-Whitney instead of a t-test?

Accepted Answer

Use Mann-Whitney when the group sizes are small or normality is doubtful; use Welch's t-test when the data are approximately normal but variances differ. Labreador picks the appropriate test from the data and states which one it used.

Kinetic Analysis & Group Comparison — Labreador

1Data Input