Figure 1: BPNM morphology and gravimetric analysis. Potassium phosphotungstate negatively-stained transmission electron microscopy, light microscopy of glutaraldehyde-fixed, osmium tetroxide post-fixed, 0.1% toluidine blue stained smears and gravimetric analysis were performed on purified lyophilized BPNM. Electron micrographs (A-C) demonstrate the repetitive nature of myelin lamellae (black arrows) and the absence of subcellular organelles. Scale bars represent 250 nm (A and B) and 100 nm (C). D and E show the brownish-black staining of myelin on light microscopy (original magnification 100X for D and 400X for E). Based on gravimetric analysis, BPNM was predominantly lipid, with approximately three times the amount of protein/proteolipid, as expected of peripheral nerve myelin (F). Numbers depict the relative percentages of each fraction to the total dry mass. Insoluble residue consists of predominantly large protein aggregates.