Upload plate reader time-series data and compute initial reaction rates. Automatic linear region detection, blank subtraction, and path length correction. Data never leaves your browser.
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Load example kinetic-assay data to see the full workflow
When to use
Do not use for
With only 3-4 early points, a single outlier dominates the slope. Collect data at 15-30 second intervals for at least 5-10 minutes to get a robust linear fit with ≥5 points in the window.
The same volume in a flat-bottom vs. round-bottom 96-well plate gives different path lengths. Calibrate by measuring a known-absorbance solution in your specific plate type, or use the manufacturer’s empirical formula.
For an enzyme assay, blanks contain buffer + substrate but no enzyme. For an inhibitor screen, blanks contain enzyme + substrate but no inhibitor (this is your 100% activity control, not a true blank).
Plate readers often show a curved start to the time-course as the plate equilibrates from room temperature to reading temperature. Allow 5-10 minutes of pre-incubation, or exclude the first few time points from analysis.
Ordinary least-squares linear regression within a sliding window. Auto-detection selects the window with highest above a user-defined threshold (default 0.99). Blank subtraction uses the mean across all blank well time points.
Last validated 2026-04-05. Calculations are designed for planning and documentation support; verify procurement decisions against manufacturer specifications or institutional SOPs.
ConductScience Kinetic Assay Analyzer (v1.0). ConductScience, Inc. 2026. Available at: https://conductscience.com/tools/kinetic-assay-analyzer
Bisswanger H. Enzyme assays. Perspectives in Science. 2014;1(1-6):41-55. doi:10.1016/j.pisc.2014.02.005
The initial rate (V₀) is measured during the linear phase of the reaction — typically the first 5-10% of substrate conversion. During this phase:
• [S] [S]₀ (substrate is essentially unchanged) • [P] is small (no significant product inhibition) • The enzyme is saturated at its working [S]
The slope of the time-course during this phase equals V₀. This tool automates the identification of this linear region using -based sliding window detection.
Two corrections are often needed for plate reader data:
