BiP is a protein in the lumen of the ER. In order to evaluate DiOC6(3) staining, double labeling with DiOC6(3) and anti-BiP was done. CV-1 cells were fixed in glutaraldehyde, stained with DiOC6(3) then photographed. The cells were then put into cold methanol and processed for immunofluorescence using anti-BiP. A comparison of the staining showed that the network stained by DiOC6(3) is also stained by anti-BiP. DiOC6(3) also stains other organelles, including mitochondria. This is shown in the following two image movie (149K) (I have not figured out how to preserve image quality in animations, so the image quality here is not as good as it should be). Scale bar = 10 microns. Arrow in DiOC6(3) image points to a mitochondria that is not labeled in the anti-Bip image.