Identification of single HRS cells in cell suspension.

A single cell suspension was prepared from a lymph node involved by HL, stained with an anti-CD30 antibody coupled to phycoerythrin, and viewed under an inverted fluorescence microscope as previously described.23 A single HRS cell is identified by its large size, bilobed nucleus with prominent nucleoli, and CD30 expression (arrow). Note smaller CD30-negative cells in the background (arrowheads).