A Low-Cost and Scalable pH Assay for Microplate-based Growth Experiments

Electrochemical probe-based pH measuring methods require specialized equipment and seconds-to-minutes per sample. Faster methods estimate pH using indicator dyes by visual comparison to a standard chart; however, colorimetric pH estimates lack precision and rely on human interpretation. We combined low-cost dye indicators with absorbance plate readers and a predictive model to develop a low-cost and automation-compatible pH assay for microplate-based experiments.