Fig. 4. Immunogold labeling and electron microscopy of EGFP-rab5aQ79L-expressing cells. EcR293pIND-Hygro /EGFP-rab5aQ79L cells were grown in the presence of ponasterone for 72 hours, then fixed in 4% PFA and processed for immunogold labeling and electron microscopy as described in Materials and Methods. EGFP, 6 nm gold (arrowheads); LAMP-2, 12 nm gold (arrows); M, mitochondrion. Magnification, 65,000x.