FIG. 6.
Double labeling of MHV-infected cells with CT1a and LAMP-1 and with internalized 16-nm gold–BSA. Panel A shows cryosections of MHV-infected cells fixed at 5 h p.i. and double labeled with CT1a (small arrows, 5-nm gold) and LAMP-1 (arrowhead, 10-nm gold). In this particular profile, the CT1a-positive membranes are quite close to the plasma membrane (P). Panel B shows L cells that were filled with 16-nm gold–BSA (large arrowhead) that was chased overnight into late endosomes/lysosomes prior to MHV infection. Cells were fixed at 5 h p.i. and double labeled with antibodies to CT1a (arrowheads, 10-nm gold). Bars, 100 nm.