Isolation of murine natural killer cells

This unit describes the isolation of natural killer (NK) cells from mouse spleen. The basic protocol describes a method for preparing a highly purified NK cell population from mouse spleen by cytotoxic depletion of contaminating cells with selected monoclonal antibodies (MAbs), complement lysis, and density-gradient centrifugation to eliminate dead cells. The advantage of this negative selection process is that the NK cells are not coated with antibody and, therefore, are not at risk of activation by antibody cross-linking. Purity can then be assessed by cell surface phenotype.