Pi-seq—A customizable multichannel syringe pump for microfluidics

Abstract

The advent of single cell technologies resulted in growing demand for microfluidics in the biological sciences. Commercial platforms have remained expensive, inflexible, and non-customizable black boxes. We developed an open source, multichannel, zero-backflow microfluidics device based on syringe pumps controlled by a Raspberry Pi computer. It uses both readily available and 3D-printed parts as well as a custom PCB and is easily serviceable. Moreover, it is fully customizable for various applications. Total cost is under €600. We equipped one channel with a custom Peltier-based temperature controller for precise heating or cooling and a mixer mechanism to prevent sedimentation of the cells within the syringe. Depending on the cells in the sample, heating and cooling can be useful to maintain a beneficial environment or to slow down cellular processes and cell death, respectively. Combined with microfluidics consumables and a microscope, the device is capable of integration into a high quality droplet-based single cell RNA sequencing workflow as shown here. Analysis of a mixture of human and insect cells resulted in a dataset of 17,769 single cells and demonstrates reliable operation and separation.