KF-80快速冷冻技术制备生物样品用于电镜X射线元素分析

The Preparation of Biological Specimen by Using KF-80 Rapid Cryofixation for Electron Probe X-ray Microanalysis

新鲜生物样品经快速冷冻固定、冷冻超薄切片后进行电镜下形态观察和在位元素分析 ,以研究细胞生命活动某个瞬间的形态及元素组成和分布 .KF 80快速冷冻仪用液氮使氟里昂 - 2 2保持在 - 16 0℃ ,将生物样品快速射入其中以达到快速冷冻固定的目的 .在组织样品———大鼠胸主动脉平滑肌细胞和悬滴样品———兔红细胞的观察中证实两者的超微结构保存较好 ,虽有直径约 0 1μm的小冰晶存在 ,但不影响形态观察和元素分析 .平滑肌细胞X射线元素分析结果显示 ,胞质中钾含量高 ,钠含量低 ;核中磷含量高而硫含量低 ,说明此项技术能保持胞质与胞核间元素分布的差异 .

Ultrathin cyosections of fresh biological specimen fixed by rapid freezing are used for studying the instantaneous form of cell life activity and their elemnt composition by electron microscopy and electron'probe X ray microanalysis. The KF 80 rapid cryofixation system keeps the cryogen Freon 22 at a temperature of -160 ℃ through the use of liquid nitrogen. The biological specimen is injected rapidly into the cryogen to realize the purpose of rapid cryofixation. Through the observation of a tissue sample -- rat thoracic aorta smooth muscle and a droplet sample -- rabbit crythrocytes, it is proved that the cell ultrastructure of both samples were well preserved. Although some ice crystal of about 0 1 μm in diameter appeared,they were too small to affect the ultrastructure and the element anslysis. The X ray microanalysis of the smooth muscle cells demonstrated high potassium and low sodium content in the cytoplasm,and high phosphor and low sulphur content in the nucleus,indicating that the KF 80 cryofixation system can maintain the difference of element distribution between the cytoplasm and nucleus.