Analysis and purification of innate lymphoid cells in human intestine and blood by flow cytometry

The role of innate lymphoid cells (ILCs)—including natural killer cells, helper-like ILC1s, ILC2s, ILC3s, and lymphoid tissue inducers—in human cancer is still poorly understood due to the scarcity of cell number. To address this, we present a protocol to analyze or purify ILCs from human blood, adjacent intestine, and colorectal tumor tissue. We describe steps for tissue and blood treatment, density centrifugation, antibody staining, and cell sorting. For complete details on the use and execution of this protocol, please refer to Qi et al. (2021).1