Preparing Tissue for Electron Microscopy

Rapid Freezing for Electron Microscopy

Rapid freezing, or cryofixation, is a crucial step in preparing tissue samples for electron microscopy. This technique helps preserve cellular structures by minimizing ice crystal formation that can damage the delicate components of the tissue. By rapidly freezing the sample, the biological structures are fixed in their natural state, providing a more accurate representation of the specimen.

Cryoultramicrotomy for Sectioning

After cryofixation, the frozen tissue sample is sectioned at low temperatures using cryoultramicrotomy. This process allows for thin sections of the tissue to be obtained without the need for chemical fixation, providing high-resolution images for electron microscopy analysis. Sectioning at low temperatures helps maintain the integrity of the cellular structures.

Coating with Heavy Metal for Enhanced Contrast

To improve conductivity and contrast in electron microscopy, the sections are coated with a heavy metal. This coating helps enhance the visibility of cellular structures under the electron beam, allowing for better imaging and analysis. Metals such as platinum are commonly used for this purpose.

By utilizing rapid freezing, cryoultramicrotomy, and heavy metal coating, researchers can prepare tissue samples for electron microscopy without the need for fixatives. This method preserves the biological structures more accurately and provides high-quality images for detailed analysis.