Isolation of Ly-1+/CD5+ B cells by cell sorting

Richard R Hardy1

  • 1Fox Chase Cancer Center, Philadelphia, Pennsylvania, USA.

Ly-1/CD5 is a 68-kDa glycoprotein that was originally thought to mark the helper subset of T cells. Later it was shown to be present on all T cells and, more recently, on a subset of B cells. Although its function remains the subject of speculation, CD5 expression serves as a useful marker for a functionally distinct population of B cells that has attracted a considerable amount of interest from investigators of both murine and human immune systems. Of critical importance in much of this work is the isolation of pure populations of CD5+ B cells along with appropriate control populations. A flow cytometry technique is presented in this unit, which results in the selection and isolation of two populations of cells from a complex mixture based on physical properties (e.g., size and internal granularity) and correlated expression of several surface molecules.