Title: Targeting individual cells by barcode in pooled sequence libraries Authors: Navpreet Ranu, Alexandra-Chloé Villani, Nir Hacohen, and Paul C. Blainey

There is rising interest in applying single-cell transcriptome analysis and other single-cell sequencing methods to resolve differences between cells. Pooled processing of thousands of single cells is now routinely practiced by introducing cell-specific DNA barcodes early in cell processing protocols ​. However, researchers must sequence a large number of cells to sample rare subpopulations ​ , even when fluorescence-activated cell sorting (FACS) is used to pre-enrich rare cell populations. Here, a new molecular enrichment method is used in conjunction with FACS enrichment to enable efficient sampling of rare dendritic cell (DC) populations, including the recently identified AXL​SIGLEC6​ (AS DCs) subset​, ​ within a 10X Genomics single-cell RNA-Seq library. DC populations collectively represent 1-2%