Human CD19+CD27+ memory B cells from Creative Bioarray are isolated from peripheral blood mononuclear cells. Cells expressing CD2, CD14, CD16, CD36, CD43, and CD235a are depleted from the mononuclear cell population using immunomagnetic particles leaving an enriched CD19+ fraction. CD27+ cells are then enriched from the CD19+ fraction using immunomagnetic anti-CD27 particles leaving purified CD19+CD27+ memory B cells.