Specimen preparation is a critical step in TEM. The process typically involves the following steps:
1. Fixation: Preserves the biological material using chemical fixatives like glutaraldehyde and osmium tetroxide. 2. Dehydration: Removes water from the specimen using a series of alcohol or acetone baths. 3. Embedding: The specimen is embedded in a resin block to provide support. 4. Sectioning: Ultra-thin sections (50-100 nm) are cut using an ultramicrotome and collected on a TEM grid. 5. Staining: Sections are stained with heavy metals (e.g., lead citrate, uranyl acetate) to enhance contrast.