Growth Curve Analysis

A Shiny app

MDPhan

Bacterial growth in liquid medium

  1. Bacterial growth: increase in number of bacterial cells by division
  2. Optical density (Absorbance): measurements produced by a spectrometer to estimate the number of bacterial cells in liquid medium
  3. Growth curve: a kinetic line following the change in optical density (i.e. bacterial growth) in time (hours).
  4. Comparing bacterial growth requires estimation of growth curve parameters and statistical testing (Anova and Dunnett post-test)

Growthcurves

Growth curves

Below is the growth curves of 4 bacterial strains (mean \(\pm\) standard deviation, n=3).

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Parameter estimation and curve comparison

  • Parameters (mu, lambda, A and AUC) are estimated for each curve.
  • These parameters are then used to compare curves of different strains.
  • The 95% CI plot is shown below, highlighting parameters that are different from the wildtype strain.

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Conclusion

GrowthCurvesAnalysis is an online app that:

  • Allow user to upload text-delimited data file
  • Visualise growth curves (ggplot2) with option to export plot in .pdf
  • Estimate curve parameters (opm)
  • Statistical testing to compare different groups of curves (opm) and show plots of 95% confident intervals to help interpret the results.

Please visit https://mdphan.shinyapps.io/GrowthCurvesAnalysis/ to try out for yourself.

Sample data and source code are available here.

Thank you for using GrowthCurvesAnalysis!