UNIT 3.5B Isolation of Ly-1+/CD5+ B Cells by Cell Sorting

  1. Richard R. Hardy

Published Online: 1 AUG 2003

DOI: 10.1002/0471142735.im0305bs55

Current Protocols in Immunology

Current Protocols in Immunology

How to Cite

Hardy, R. R. 2003. Isolation of Ly-1+/CD5+ B Cells by Cell Sorting. Current Protocols in Immunology. 55:I:3.5B:3.5B.1–3.5B.10.

Author Information

  1. Fox Chase Cancer Center, Philadelphia, Pennsylvania

Publication History

  1. Published Online: 1 AUG 2003
  2. Published Print: JUN 2003


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.