Beginners guide to sample preparation techniques for transmission electron microscopy

Background purpose: The revolution in microscopy came in 1930 with the invention of electron microscope. Since then, we can study specimens on ultrastructural and even atomic level. Besides transmission electron microscopy (TEM), for which specimen preparation techniques will be described in this article, there are also other types of electron microscopes that are not discussed in this review. Materials and methods: Here, we have described basic procedures for TEM sample preparation, which include tissue sample preparation, chemical fixation of tissue with fixatives, cryo-fixation performed by quick freezing, dehydration with ethanol, infiltration with transitional solvents, resin embedding and polymerization, processing of embedded specimens, sectioning of samples with ultramicrotome, positive and negative contrasting of samples, immunolabeling, and imaging. Conclusion: Such collection of methods can be useful for novices in transmission electron microscopy.