| Abstract: | Microfibrillar structures can be seen in ultrathin sections of cell walls which have been post-stained with uranyl acetate and lead citrate. This stain is removable by washing, suggesting that a physical mechanism is involved. It is suggested that these structures are the cellulose microfibrils of the wall; they appear to be 3.5 nm in diameter and not fasciated into larger units. Freeze-etching of untreated tissue supports this conclusion. These two techniques seem to have many advantages over methods previously used for the study of microfibril arrangement and structure. |
