Fig. 1. Intermixing of small- and large-scale protein clusters follows a different time course. Two samples of JY cells were labeled separately with fluoresceinated and rhodaminated anti-MHC-I Fabs (W6/32), respectively. The two separately labeled samples were subsequently fused. Temporal changes in FRET efficiency between fluoresceinated and rhodaminated W6/32 Fabs () and overlap of fluorescein and rhodamine clusters () were measured. The filled bar on the right displays the FRET efficiency measured between fluoresceinated W6/32 and rhodaminated W6/32 on a double-labeled, non-fused JY cell sample, whereas the white bar shows the overlap of fluoresceinated W6/32 and rhodaminated W6/32 clusters on similarly labeled cells. Results are mean±s.e.m.