Tool · Microbiology
Growth Curve Analyzer
Plate-reader growth curves in; growth rate, doubling time and lag out.
- Web app
- Runs in your browser
- Synthetic demo data
- Made with Claude
- 17 September 2026
Give it the CSV export from a plate reader: a Time column, then one column of optical density (OD) readings per well. Mark the medium-only wells as blanks and it subtracts them from every well; group replicate wells and it reports each group as mean ± SD. For each well it finds the steepest stretch where ln(OD) rises in a straight line over time, and from that reports the maximum specific growth rate (μmax), doubling time and lag time, along with maximum OD and area under the curve. Results export as CSV. It does not fit growth models such as Gompertz or logistic curves.
Your file stays on your computer. It is read and analysed by JavaScript in this browser tab; nothing is uploaded or saved.
Drop a plate-reader CSV anywhere on this page
Or use Open CSV… above. No file handy? Load demo data opens a made-up 96-well plate.
The file needs a Time column followed by one column per well (A1, A2, …). Extra rows above the table, like in BioTek or Tecan exports, are fine.
Plate
Click a well to select it. Shift- or Cmd/Ctrl-click, or click and drag, to select several. Row letters and column numbers select a whole row or column. On a touch screen, tap wells to add or remove them.
Growth curves
On a log scale exponential growth is a straight line. The dashed line is the fitted growth line; where it meets the starting OD is the end of the lag phase.
Group summary
Mean ± SD (standard deviation) across the wells of each group; n = wells that went into the number. Tick a group to draw its mean ± SD ribbon in the plot.
| Plot | Group | Wells | μmax (1/h) | Doubling time (min) | Lag (h) | Max OD |
|---|
Results per well
Click a column header to sort. All OD values are blank-corrected.
What do these numbers mean?
- OD (optical density, usually at 600 nm)
- How cloudy the well is. More cells scatter more light, so OD goes up as the culture grows.
- Blank
- A well with medium but no cells. Its OD (plastic + medium) is subtracted from every other well at each time point. Without blanks all rates come out too low.
- μmax (1/h)
- Maximum specific growth rate. During exponential growth ln(OD) rises in a straight line; μmax is the slope of the steepest straight stretch.
- Doubling time (min)
- How long the culture takes to double at its fastest: ln(2) / μmax.
- Lag (h)
- Time before exponential growth starts: where the fitted growth line, extended backwards, crosses the starting OD.
- AUC (OD·h)
- Area under the curve. One number that sums up lag, rate and yield; handy for wells that barely grow.
- R²
- How well a straight line fits the chosen stretch of ln(OD). 1 is perfect; below 0.95 the stretch is rejected.
- No growth
- The well never rose enough, or never grew steadily enough, to fit a rate. No rate is reported rather than a made-up one.
How it was made
Like the projects in the Notebook, this was made with Claude, Anthropic's AI model, which wrote the code and its tests. Wells that never grow steadily are reported as “no growth” with a reason, never with an invented rate.