BIOLOGICAL APPLICATIONS OF A COMPUTER CONTROLLED ANALYTICAL ELECTRON MICROSCOPE

电子能量损失谱是通过电子能谱获得的。 由后光谱仪组成的GaTan并行探测器系统 四极透镜，一个YAG闪烁体，光纤耦合，一个 光电二极管阵列和相关电子设备。探测器 量子效率被测量并发现接近于1， 提供了大约1000倍的改进 常规的光谱连续记录。能量分辨率为 在100keV的束流能量下，获得了约1.5 eV的激光输出。光谱与 良好的计数统计可以在100毫秒内被记录， 从而允许执行实时鳗鱼。初步数据 是从一些氟类似物中获得的 神经递质，表明这种化合物可能是 在生物上有意义的浓度下可以检测到 积分时间为1秒。也有可能监控 通过观察辐射损伤和质量损失来实时 有机材料中氮、氧、氟芯边的衰变 分子。

Electron energy loss spectra have been obtained by means of a Gatan parallel detector system consisting of Post-spectrometer Quadrupole lenses, a YAG scintillator, fiber-optic coupling, a photodiode array and associated electronics. The detector quantum efficiency was measured and found to be close to unity, giving approximately a 1000-fold improvement over the conventional serial recording of spectra. An energy resolution of about 1.5 eV was achieved at 100 keV beam energy. Spectra with good counting statistics could be recorded in 100 milliseconds, thus allowing real-time EELS to be performed. Preliminary data have been obtained from some fluorine analogs of neurotransmitters, indicating that such compounds might be detectable at biologically meaningful concentrations with an integration time of 1 second. It has also been possible to monitor radiation damage and mass loss in real-time by observing the decay of nitrogen, oxygen and fluorine core edges in organic molecules.