Grote M
Institute of Medical Physics, Münster University, FRG.
J Histochem Cytochem. 1989 Jul;37(7):981-7. doi: 10.1177/37.7.2499622.
The exine of birch pollen was examined by scanning and transmission electron microscopy in the native state and after fixation in different aqueous fixatives: glutaraldehyde + OsO4; glutaraldehyde + cetylpyridinium chloride (CPC) + OsO4; glutaraldehyde + cuprolinic blue (CB); and periodate + lysine + paraformaldehyde (PLP). The native pollen exine showed a thin (3-5-nm) border of electron-dense material lining the tectum and electron-dense material within microchannels and bacula cavities. Fixation with the addition of CPC resulted in a voluminous surface coat surrounding the pollen grain, but empty microchannels and bacula cavities. After fixation with the addition of CB, there was a thin surface coat, whereas microchannels and bacula cavities were partially filled with electron-dense material. The other fixatives led to empty microchannels and bacula cavities. There was no surface coat on the pollen grain. However, after all fixation procedures, a thin electron-dense border of the tectum remained visible. Concerning the electron-dense material filling microchannels and bacula cavities in the native pollen grain, the results obtained in the present study suggest that it is either completely lost (after conventional and PLP fixation) or, after fixation with a precipitating additive, partially (CB) or completely (CPC) solubilized and precipitated on the surface of the pollen grain as a surface coat.
采用扫描电子显微镜和透射电子显微镜，对天然状态以及经不同水性固定剂固定后的桦树花粉外壁进行了观察：戊二醛+四氧化锇；戊二醛+十六烷基吡啶氯化物（CPC）+四氧化锇；戊二醛+铜试剂蓝（CB）；高碘酸盐+赖氨酸+多聚甲醛（PLP）。天然花粉外壁在覆盖层内侧呈现出一层薄（3 - 5纳米）的电子致密物质边界，微通道和棒状体腔内也有电子致密物质。添加CPC固定后，花粉粒周围形成了一层厚厚的表面涂层，但微通道和棒状体腔为空。添加CB固定后，有一层薄的表面涂层，而微通道和棒状体腔部分填充有电子致密物质。其他固定剂导致微通道和棒状体腔为空，花粉粒上没有表面涂层。然而，在所有固定程序后，覆盖层的薄电子致密边界仍然可见。关于天然花粉粒中填充微通道和棒状体腔的电子致密物质，本研究结果表明，它要么完全丢失（常规固定和PLP固定后），要么在用沉淀添加剂固定后，部分（CB）或完全（CPC）溶解并沉淀在花粉粒表面形成表面涂层。
