Full-length Ebola GP localizes in the ER in close proximity to the nuclear membrane. A. HEK293T cells were transiently transfected with 10 μg GP (pCB6-EbGP) plasmid for 24 hours. Cells were fixed and stained for DNA (blue) using Hoechst, nuclear pore complex (NPC, red) proteins using mouse monoclonal antibody 414 (Covance Research Products), and GP (green) using the neutralizing human monoclonal antibody (KZ52) labeled with a Zenon labeling kit (Molecular Probes). Scale bar represents 15 μm. Side panels show individual fluorescent channels from the boxed region in the image. B. HEK293T cells were transiently transfected for 24 hours with 8 μg GP and 2 μg pDsRed2-ER vector (Clontech) that labels the endoplasmic reticulum (ER, red). Cells were fixed and stained for late endosomes using a mouse monoclonal antibody targeting CD63 (BD Biosciences, blue), in accordance with a previous publication . GP was stained as above (green). Scale bar represents 15 μm. Side panels show individual fluorescent channels from the boxed region in the image.