BioSamplr: An open source, low cost automated sampling system for bioreactors

Abstract

Autosampling from bioreactors reduces error, increases reproducibility and offers improved aseptic handling when compared to manual sampling. Additionally, autosampling greatly decreases the hands-on time required for a bioreactor experiment and enables sampling 24 h a day. We have designed, built and tested a low cost, open source, automated bioreactor sampling system, the BioSamplr. The BioSamplr can take up to ten samples from a bioreactor at a desired sample interval and cools them to a desired temperature. The device, assembled from low cost and 3D printed components, is controlled wirelessly by a Raspberry Pi, and records all sampling data to a log file. The cost and accessibility of the BioSamplr make it useful for laboratories without access to more expensive and complex autosampling systems.

Keywords: Automation; Bioengineering; Fermentation; Liquid-handling.

Graphical abstract

Fig. 1

a) A picture of an assembled BioSamplr system including: (b) the Cartesian System, which moves sampling needle to the appropriate sample on the (c) Sample Block, which holds and chills up to 10 microfuge tubes. Samples are drawn from a reactor by a (d) Pump and Valve System. This system uses a peristaltic pump to draw liquid (sample and or cleaning solution) or air into the system. Pinch valves control which medium is pumped. e) The electronics including a Raspberry Pi Controller are contained in a housing underneath the other components.

Fig. 2

Temperature profile over time of the sample block (blue line) and radiator (red) line. Temperatures were monitored over 30 h with a sample block temperature setpoint of 4 °C setpoint. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)

Fig. 3

Sampling consistency for 6 runs of 10 samples (60 samples in total) all set to sample 0.75 mL.

Fig. 4

Comparison of data obtained from manual samples with those taken by the BioSamplr in actual fermentations. Cell free samples were taken and stored at 4 °C . Optical density (black circles, manual samples), glucose measurements (gray circles and lines), pyruvate measurements (red circles and lines). Dashed lines indicate data from manual samples, whereas solid lines indicate samples taken with the BioSamplr. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)