Structural and Molecular Virology Group

Transmission electron microscopes typically use high energy electron beams transmitted through very thin samples in order to analyze the microstructure of materials. Electrons are accelerated at several hundred KV, resulting in wavelengths much smaller than that of light, and are focused with electromagnetic lenses for imaging. Images of samples generated are recorded on digital camera. The TEM facility at IIT Delhi consists of a 200 KV TEM, with a high brightness field-emission gun (FEG) source which produces improved sensitivity and resolution compared to more traditional thermionic sources like LaB6 or Tungsten filaments. Collected images provide detailed information about the size, shape and morphological details of materials. This facility can also be utilized for high resolution analysis of the structure and organization of large biological molecules such as protein complexes, viruses etc through cryoelectron microscopy. This technique involves freezing biological material quickly in vitreous ice and imaging at temperatures less than -180°C. Accessory equipment for plunge freezing samples, plasma cleaning grids and holders are available.