实现生物单分子成像的液相扫描电镜新技术

Application of Liquid Scanning Electron Microscopy in Single Molecule Characterization of Biological Samples

细胞膜蛋白的定位和分布在疾病发生发展中起着重要的作用,而原位表征纳米级膜蛋白需要单分子水平技术。为实现生物样品的原位液态环境高分辨成像,发展了一套基于扫描电镜液体环境的单分子成像技术。该技术采用扫描透射成像装置和商业化液体芯片装置组合,利用该技术观察了三阴性乳腺癌细胞膜蛋白表皮生长因子受体的精确定位、分布和聚合态。结果表明,采用高真空环境大约10~(-4) Pa、加速电压30 kV、束流约10~(-10) A实验参数,液体环境扫描透射成像模式,图像分辨率达到2~3 nm。标定膜蛋白的量子点ZnS@CdSe和Au纳米颗粒,具有相对于生物和液体更高的原子序数,因此在成像中形成了更好的衬度和信噪比。该技术为解决细胞生物学领域的高分辨单分子成像提供了一种先进的原位研究方法和直观观测平台。

The localization and distribution of cell membrane proteins play an important role in the occurrence and development of diseases,and in-situ characterization of nanoscale membrane proteins requires single molecule level technology.To achieve high-resolution imaging of biological samples in the liquid environment,a single molecule imaging technology based on scanning electron microscopy(SEM)was developed.A combination of scanning transmission imaging device and a commercial liquid chip device were used to observe the distribution and polymerization state of membrane protein EGFR in triple negative breast cancer(TNBC)cells.Results show that the images resolution reaches about 2-3 nm.The experimental conditions of the ESEM included an accelerating voltage of 30 kV,a beam current of 10-10 A in a high vacuum environment.Because ZnS@CdSe quantum dots and gold particles have higher atomic number than liquids and organisms,better contrast and signal-to-noise ratio in imaging were obtained.This technology provides an advanced in-situ method and observation platform for high-resolution imaging in the cell biology field.