Department of Botany, University of Georgia, Athens, Georgia 30601.
Plant Physiol. 1972 Feb;49(2):166-71. doi: 10.1104/pp.49.2.166.
Freeze-substitution and Epon embedment were quantitatively evaluated for their effectiveness in retaining water-soluble metabolites in plant tissues. Roughly 99% of the 80% (v/v) ethanol-extractable radioactivity in photosynthetically labeled soybean leaf discs and in petiole fragments containing translocated (14)C was retained during freeze-substitution in acetone or propylene oxide and embedment in Epon. Substantially more activity was lost from (14)C-sucrose-infiltrated pith blocks, but most or all of this loss came from the block surface. The procedure was effective for a sucrose concentration as low as 0.004%. Sections floated on water retained most of their (14)C-sucrose, and high resolution autoradiographs could easily be prepared without resorting to dry procedures. Embedded (14)C-sucrose was apparently chemically unreactive, since there was no loss of radioactivity when sections were stained with the periodic acid-Schiff reagent, nor did the embedded sucrose show staining.
为了评估冷冻固定和环氧树脂包埋在保留植物组织中水溶性代谢物方面的效果，我们对其进行了定量评估。在光合作用标记的大豆叶片圆盘和含有转运（14）C 的叶柄片段中，大约 99%的 80%（v/v）乙醇提取物放射性在丙酮或丙烯氧化物中冷冻固定和环氧树脂包埋时得以保留。从（14）C-蔗糖渗透的髓质块中丢失了更多的活性，但大部分或全部损失来自块表面。该程序对蔗糖浓度低至 0.004%也有效。漂浮在水面上的切片保留了大部分（14）C-蔗糖，并且可以轻松制备高分辨率的放射自显影图，而无需采用干燥程序。嵌入的（14）C-蔗糖显然没有化学反应活性，因为当用过碘酸-Schiff 试剂染色切片时，放射性没有损失，嵌入的蔗糖也没有染色。
