Cost-Effective Live Cell Density Determination of Liquid Cultured Microorganisms
Live monitoring of microorganisms growth in liquid medium is a desired parameter for many research fields. A wildly used approach for determining microbial liquid growth quantification is based on light scattering as the result of the physical interaction of light with microbial cells. These measurements are generally achieved using costly table-top instruments; however, a live, reliable, and straight forward instrument constructed using parts that are inexpensive may provide opportunities for many researchers. Here, such an instrument has been constructed and tested. It consists of modular test tube holding chambers, each with a low power monochromatic light-emitting diode, and a monolithic photodiode. A microcontroller connects to all modular chambers to control the diodes, and send the live data to either an LCD screen, or a computer. This work demonstrate that this modular instrument can determine precise cell concentrations for the bacteria Escherichia coli and Pseudomonas syringae pv. tomato DC3000, as well as Saccharomyces cerevisiae yeast.
Jacob would like to acknowledge ENERSENSE, NTNU for their support of this research. Alexander would like to thank Prof. Dr. Ralph Hückelhoven and Dr. Stefanie Ranf for providing lab equipment and consumables. We further would like to acknowledge Florian Lücking for printing the first prototypes and for general 3D-printing support. Special thanks goes to Florian Fäth, CEO of the Fäth GmbH (Eschau-Hobbach, Germany) for financial support to purchase a 3D-printer, making this research possible.
Compliance with Ethical Standards
Conflict of interest
The authors declare that they have no conflict of interest.
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