Double-labeling techniques. (A) EBER-ISH and CD20 double-labeling showed in this case large CD20⁺ B cells (arrows) showing a purplish nuclear staining corresponding to EBERs (original magnification ×400). (B) In another case, EBER-ISH and CD2 double-labeling showed clusters (arrow) of CD2 and EBER-ISH–positive cells (original magnification ×400).