Mallory's phloxine B-methylene blue-azure II stain emphasizes elastin and collagen bundles in epoxy embedded lung

A version of Mallory's phloxine-methylene blue-azure II technique suitable for large epoxy sections is described. Phloxine B (C.I. 45410) and a yellow-green interference filter (546-548 nm transmission) combine to give high contrast monochrome images. By comparing light micrographs of lung parenchyma entirely unstained or stained only with phloxine B against electron micrographs of the same material, it is seen that phloxine B emphasizes essentially only elastin and collagen fiber bundles. The technique has produced images useful for investigating lung parenchyma architecture and micromechanics.