A microfluidics-free centrifugally-driven nano-liquid pipetting system (CNPS) for single-cell whole genome amplification

Abstract

We developed a microfluidics-free centrifugally-driven nano-liquid pipetting system (CNPS) for single-cell whole genome amplification. The capillary tube and the collection vessel (PCR tube or 96-well PCR plate), both of which are easily accessible, make up the basic components of the system. Unlike microfluidic chips that need a clean room and special skills to fabricate, the CNPS can be assembled in the typical biology laboratory without any special training. Centrifugation is used to directly pipette the nanoliter-volume liquid into the collection tube, which eliminates the requirement for extra equipment. The CNPS, which is compatible with the standard handheld pipette, allows for a smooth transition between the micro and macro worlds, thereby overcoming the problem of retrieving nanoliter-volume products. We further demonstrated the feasibility of the CNPS for nanoliter-volume single-cell multiple displacement amplification. Based on the sequencing results, the mapped reads cover on average 95.23%, 95.15%, and 80.94% for Saccharomyces cerevisiae, Escherichia coli, and Staphylococcus epidermidis, respectively. In sum, the CNPS has the potential to become an alternative powerful platform for single-cell genome sequencing with the ability to manipulate ultra-small volumes, as well as to enhance precision and sophistication by significantly minimizing sample losses and reducing amplification bias.