MicrobeMeter is an open-source, high-resolution photometer with continuous measurement and wireless capabilities. It is designed to measure growth dynamics of test tube grown cell cultures.
MicrobeMeter is an open-source, high-resolution photometer with continuous measurement and wireless capabilities.
MicrobeMeter is a high-resolution photometer with continuous measurement and wireless capabilities. It allows measuring of microbial growth dynamics, as used in many disciplines of life sciences, such as molecular biology, systems biology and synthetic biology. MicrobeMeter is made using 3D-printing and open-source single-board microcontroller technologies (Arduino), combined with a purpose-built electronic circuit. MicrobeMeter shows high performance compared to the commercial bench-top spectrophotometers, and allows reliable continuous measurements up to 458 hours from both aerobic and anaerobic cell cultures. The resulting high-resolution growth data provides an invaluable source for estimating key kinetic parameters for microbial physiology modelling. See the preprint of MicrobeMeter on bioRxiv for more details.
Four measurement ports
MicrobeMeter has four measurement ports. This allows a simple experiment design, where three ports can be used with replicate samples of the same cell culture, and one port for a blank (i.e. non-inoculated media).
Bluetooth data transfer
MicrobeMeter measurements are communicated to any computer (Windows or Mac or Linux) in realtime via Bluetooth. Currently, MicrobeMeter can perform data acquisition at intervals as low as six seconds.
MicrobeMeter is powered using a rechargeable battery, which can support up to 4 days of continuous measurement. The auto-reconnect feature of MicrobeMeter allows swapping batteries during continuous measurement without losing wireless connection to a computer.
MicrobeMeter can be used for measuring cell cultures that require oxygen for growth (aerobic) or not (anaerobic). For the latter case, MicrobeMeter makes use of the commonly used Hungate tubes, which can allow growth of any anaerobic organism.
MicrobeMeter has a low footprint, that allows it to be used in controlled environments such as shaking incubators or containment chambers. It can even be used on the field. Current design of MicrobeMeter requires it to be placed in a shaking incubator for best performance.
MicrobeMeter supports fully programmable measurement routines. Users can easily set the measurement frequency using the data acquisitions program (maximum measurement frequency is 6 seconds).
Besides its use in professional research, MicrobeMeter makes it also possible to develop an integrated teaching mini-module, in which students can go from building their own measurement device, implementing it in the laboratory, and using the resulting data for modelling of microbial population dynamics. The resulting experience will provide an understanding of the meaning and limitations of optical measurements and their role in quantitative biology.
MicrobeMeter is capable of taking continuous measurements over a long period of time. This plot shows anaerobic growth of Desulfovibrio vulgaris measured every five minutes for 4 days (1154 data-points).
Highly stable design
MicrobeMeter produces very low device-to-device variability and offers a large measurement range. This image shows a performance-test, in which the light intensity was decreased step-by-step to simulate microbial growth (x-axis). The readings from the four different ports of MicrobeMeter show highly linear intensity response (top panel) and low port-to-port variability (bottom panel; black dot is the mean and grey bar is the standard deviation).
MicrobeMeter can be placed in a plastic jar for protection when using it for fieldwork or in an incubator. Current design requires MicrobeMeter to be placed in a shaking incubator or otherwise shaken before each measurement for best performance (i.e. to avoid sedimentation of cells).