Isolation of human B cell populations.

To study the function and biology of human B cells, it is necessary to isolate pure populations. Historically, B cells were enriched by the sequential depletion of monocytes, natural killer cells, and T cells. However, this time-consuming process has been superseded by sorting methods using specific antibodies, targeting, in negative-selection strategies, unwanted cell types, or, in positive-selection strategies, B cell markers such as CD19. Here we describe in detail four methods for isolating B cells from human blood or mononuclear cells, and discuss how these techniques can be combined with fluorescent cell sorting for the characterization of specific B cell populations.