Data for high-throughput measurements of microbial growth kinetics are typically generated using automated optical density (OD) measurements from microtiter plate readers. There may be significant bias in these measurements which often goes unrecognized, in particular due to variation in background OD measurements and initial cell counts. Curve fitting methods may fail due to atypical growth curves. MicroplateGR4 software was developed to automate the analysis of microtiter plate optical density data from microtiter plate readers, identify sources of error, and generate repeatable and accurate microbial growth kinetics measurements. Example data is included; files consist of Nx97 comma delimited data files consisting of rows (A-H) and columns (col) (1-12). The first column is elapsed time in hours, and subsequent columns are data from 96 well microtiter plates in row-dominant order (A1, A2, A3 ... H11, H12). Microtiter plates were prepared following the general protocol of Anthony and Breidt (protocols.io, https://www.protocols.io/view/microtiter-plate-microbial-growth-measurements-n2bvjny5bgk5/v1).

EX231020 DifficultCurves.csv, 48 x 97 spreadsheet with OD data, first col is elapsed time, hours (h). Replicate data cells in columns with rows containing 1:2 serial dilutions for the initial OD. No-cell controls included Artificial Cucumber Juice Medium (ACJ), a laboratory medium with similar nutrients as cucumber juice, (col 11) and cucumber juice (CJ, col 12), replicated for all rows. Data for Leuconostoc mesenteroides LA81 in ACJ medium was in cols 1,2, with CJ medium in cols 5,6. Data for Lactiplantibacillus pentosus LA445 in ACJ was in cols 3,4, and for CJ medium, cols 7,8.

EX240801 B200.csv, 96 x 97 spreadsheet with OD data, first column is elapsed time, 0.5 h. Data included cols 2 and 4 with Escherichia coli B200 in CJ medium (serial dilutions for rows A-F), with controls in cols 11 and 12 (all rows).

EX250319 microplate.csv, 192 x 97 spreadsheet with OD data, first column in elapsed time 0.25 h. Data included serial 2-fold dilutions (rows A-H) for Lactiplantibacillus pentosus LA445 in columns 1-3 with ACJ medium, columns 4-6 with CJ medium, and columns 7-9 De Man, Rogosa and Sharpe (MRS) medium (a commercial laboratory growth medium for lactic acid bacteria, from De Man, J.C., Rogosa, M., and Sharpe, M.E. (1960). A Medium for the Cultivation of Lactobacilli. Journal of Applied Bacteriology, 23(1), 130–135.). No-cell controls for ACJ (column 10), CJ (column 11), and MRS (column 12) were in all rows.

EX250319 no header.csv (same as EX250319 but without first row containing row/col labels).