Computer-aided high-throughput cloning of bacteria in liquid medium

Abstract

Bacterial cloning was first introduced over a century ago and has since become one of the most useful procedures in biological research, perhaps paralleled in its ubiquity only by PCR and DNA sequencing. However, unlike PCR and sequencing, cloning has generally remained a manual, labor-intensive, low-throughput procedure. Here we address this issue by developing an automated, computer-aided bacterial cloning method using liquid medium that is based on the principles of (i) limiting dilution of bacteria, (ii) inference of colony forming units (CFUs) based on optical density (OD) readings, and (iii) verification of monoclonality using a mixture of differently colored fluorescently labeled bacteria for transformation. We demonstrate the high-throughput utility of this method by employing it as a cloning platform for a DNA synthesis process.