Chen Heng
College of Life Sciences and Biotechnology, Shanghai Jiaotong Univeristy, Shanghai, China.
Scanning. 2007 Sep-Oct;29(5):238-42. doi: 10.1002/sca.20067.
In order to decrease salt crystal formation, reduce the aggregation of viruses in atomic force microscopy (AFM) preparations and obtain an acceptable AFM image, the AFM sampling of viruses must be optimized. In this paper, centrifugal AFM sampling of recombinant adeno-associated virus-2 (rAAV-2) was used. The prepared rAAV-2 virus was imaged by AFM using the tapping mode in air. The results indicate that the rAAV-2 viruses prepared by centrifugal AFM sampling methods could be well imaged by AFM. The rAAV-2 viruses exhibited polymorphous particles in the AFM images. The preliminary off-line section analysis of the individual rAAV-2 virus particle indicated that the half-high widths of the large rAAV-2 particles ranged from 18 to 23 nm, while those of the small rAAV-2 particles ranged from 15 to 17 nm, which is almost in agreement with the results obtained by the off-line particle analysis of the rAAV-2 virus particles. Above all, the aggregation of different-sized rAAV-2 particles was directly imaged by AFM, which verifies the previous speculation that the large number (> ~31 nm) distribution of the mean diameter of rAAV-2 virus particles was probably caused by aggregation of rAAV-2 particles.
为了减少盐晶体形成，降低原子力显微镜（AFM）样品中病毒的聚集并获得可接受的AFM图像，必须优化病毒的AFM采样。本文采用了重组腺相关病毒2（rAAV-2）的离心AFM采样。制备的rAAV-2病毒在空气中采用轻敲模式通过AFM成像。结果表明，通过离心AFM采样方法制备的rAAV-2病毒能够通过AFM很好地成像。rAAV-2病毒在AFM图像中呈现多形态颗粒。对单个rAAV-2病毒颗粒的初步离线截面分析表明，大rAAV-2颗粒的半高宽范围为18至23nm，而小rAAV-2颗粒的半高宽范围为15至17nm，这与通过rAAV-2病毒颗粒离线颗粒分析获得的结果几乎一致。最重要的是，AFM直接成像了不同大小rAAV-2颗粒的聚集，这证实了先前的推测，即rAAV-2病毒颗粒平均直径的大量（>~31nm）分布可能是由rAAV-2颗粒的聚集引起的。
