FIGURE 8.

Structure of collagen VI microfibrils as detected by electron microscopy after negative staining. Representative collagen VI microfibrils from E14.5 mouse lung composed of tetramers containing different long chains are shown. Only homotetramers were detected. The N-terminal regions of the long chains were double labeled using specific gold-labeled antibodies against the different α chains. Small gold particles (open arrowheads) always stain the α chain with the lower number, whereas the large gold particles (filled arrowheads) stain that with the higher number. Note that as the tetramers overlap the “outer” globules belong to the same tetramer, and the “inner” globules belong to the neighboring tetramers. This is indicated in Fig. 11 in a schematic drawing of the mixed α3/α6 microfibril. Scale bar, 100 nm.