A lectin-based magnetic CRISPR screening protocol permits rapid discovery of genes regulating cell-surface glycosylation

FACS-based CRISPR screening has emerged as a potent tool for dissecting the genetic networks that regulate cell-surface glycosylation. However, existing protocols are tedious and poorly suited to many cell models. We developed a lectin-based magnetic-activated cell sorting platform (Lec-MACS) that enables rapid identification of genes controlling expression of specific cell-surface glycans. Lec-MACS is faster and easier to perform than FACS-based screening while producing data of similar quality. We subsequently applied Lec-MACS to produce a genomic atlas of genes regulating breast cancer hypersialylation. This method will dramatically expand the scope and throughput of genetic screens targeted at cell-surface glycans.