Invagination of the IS membrane in frustrated conjugates. Time-lapse montages showing the large invagination of the center of the IS interface in frustrated Jurkat–Raji conjugates where the Raji cell membrane has been labeled with the membrane dye PKH26 (A) or the Jurkat membrane has been labeled with RFP-Farnesyl (B). The yellow arrowheads mark the close approximation of the labeled membranes to the GFP-Cen-2–marked MTOC that has stalled on the back side of the nucleus. See also Videos 3 and 4. Bar, 10 µm.