A versatile and low-cost open source pipetting robot for automation of toxicological and ecotoxicological bioassays

Abstract

In the past decades, bioassays and whole-organism bioassay have become important tools not only in compliance testing of industrial chemicals and plant protection products, but also in the monitoring of environmental quality. With few exceptions, such test systems are discontinuous. They require exposure of the biological test material in small units, such as multiwell plates, during prolonged incubation periods, and do not allow online read-outs. It is mostly due to these shortcomings that applications in continuous monitoring of, e.g., drinking or surface water quality are largely missing. We propose the use of pipetting robots that can be used to automatically exchange samples in multiwell plates with fresh samples in a semi-static manner, as a potential solution to overcome these limitations. In this study, we developed a simple and low-cost, versatile pipetting robot constructed partly using open-source hardware that has a small footprint and can be used for online monitoring of water quality by means of an automated whole-organism bioassay. We tested its precision in automated 2-fold dilution series and used it for exposure of zebrafish embryos (Danio rerio)–a common model species in ecotoxicology—to cadmium chloride and permethrin. We found that, compared to conventional static or semi-static exposure scenarios, effects of the two chemicals in zebrafish embryos generally occurred at lower concentrations, and analytically verified that the increased frequency of media exchange resulted in a greater availability of the chemical. In combination with advanced detection systems this custom-made pipetting robot has the potential to become a valuable tool in future monitoring strategies for drinking and surface water.

Leveraging open hardware to alleviate the burden of COVID-19 on global health systems

“…Increasingly over recent years, scientists, engineers and hobbyists alike have jointly developed and tested an impressive array of open source and state-of-the art tools that in one way or another touch all aspects of modern biology, medicine and disaster response (e.g., [12][13][14][15][16][17][18][19][20][21][22][23]). For example, in the wake of the 2011 Fukushima nuclear disaster, Safecast [9] developed FOSH Geiger counters alongside an open access logging system which led to a massive citizenscience driven map of nuclear contamination in the region [9].…”

"Do-It-Yourself" reliable pH-stat device by using open-source software, inexpensive hardware and available laboratory equipment

“…According to the literature, there is a great number of various open-source “do- it- yourself” devices, such as: a potentiostat [ 13 – 15 ], syringe pump [ 16 ], a colorimeter [ 17 ], as well as additional laboratory equipment [ 4 , 18 , 19 ], which researchers can construct and adjust to their needs at a small fraction of the cost of available commercial offers. However, to our knowledge, the open-source pH device for maintaining pH values has been constructed in a considerably smaller scope [ 20 ].…”

An Open-Source Plate Reader

“…The creation of open-source hardware for enabling molecular and cellular studies is facilitated by the ready availability of rapid prototyping techniques, low-cost opto-electronics, and commoditized microcomputers & microcontrollers. Such open-source platforms -which to date include fluorescence imagers 1-2 , spectrophotometers 3 , turbidostats 4 , robotic liquid handlers [5][6] , and multi-well plate illuminators for optogenetic stimulation 7-8 -increase access to both standard and custom laboratory apparatus alike. Here, we report the creation of an open-source plate reader (OSP), which is one of the most ubiquitous and important technologies in experimental biochemistry, biology, and bioengineering, because a plate reader permits automated and multiplexed spectrophotometric measurements.…”