Development and optimization of a process for automated recovery of single cells identified by microengraving

Microfabricated devices are useful tools for manipulating and interrogating large numbers of single cells in a rapid and cost-effective manner, but connecting these systems to the existing platforms used in routine high-throughput screening of libraries of cells remains challenging. Methods to sort individual cells of interest from custom microscale devices to standardized culture dishes in an efficient and automated manner without affecting the viability of the cells are critical. Combining a commercially available instrument for colony picking (CellCelector, AVISO GmbH) and a customized software module, we have established an optimized process for the automated retrieval of individual antibody-producing cells, secreting desirable antibodies, from dense arrays of subnanoliter containers. The selection of cells for retrieval is guided by data obtained from a high-throughput, single-cell screening method called microengraving. Using this system, 100 clones from a mixed population of two cell lines secreting different antibodies (12CA5 and HYB099-01) were sorted with 100% accuracy (50 clones of each) in approximately 2 h, and the cells retained viability.