What is the primary method for processing tissue samples in histopathology laboratories?

Paraffin embedding is the primary method for processing tissue samples in histopathology laboratories due to its ability to preserve tissue morphology and cellular detail for microscopic examination. This technique involves several steps: fixation of the tissue in formalin to prevent degeneration, dehydration through a series of alcohol solutions, clearing with a solvent like xylene, and finally embedding in paraffin wax. The paraffin serves to maintain the structure of the tissue so that thin sections can be cut with a microtome for staining and analysis. The preserved tissue maintains its histological features, allowing pathologists to make accurate diagnoses based on the microscopic appearance of the cells.

While options like embedding in resin and snap freezing are useful for specific applications such as electron microscopy or for preserving specific proteins, respectively, they are not as commonly used for routine histopathological evaluation. Smear preparation is generally used for cytological samples rather than tissue sections. Therefore, paraffin embedding remains the standard method, crucial for the comprehensive examination of tissue architecture in histopathology.