Which step follows the fixation of tissue in the histological processing sequence?

Following the fixation of tissue in the histological processing sequence, the next step is processing. The fixation process involves the treatment of tissues with fixatives to preserve and stabilize the cellular structure and morphology. After fixation, processing is essential as it prepares the tissue for embedding by removing water and replacing it with a medium that can support the tissue during subsequent steps.

Processing typically involves several stages, including dehydration, clearing, and infiltration. During dehydration, the tissues are gradually exposed to increasing concentrations of alcohol to remove water. After dehydration, a clearing agent, usually xylene, is used to eliminate the alcohol and make the tissue compatible with the embedding medium, which is often a type of paraffin wax. Finally, infiltration allows the embedding medium to permeate the tissue, creating a solid block that can be easily sectioned.

This step is crucial as it directly affects the quality of the final tissue sections that will be evaluated under a microscope. Understanding the sequence of tissue preparation is vital for histotechnologists to ensure optimal preservation and presentation of tissue specimens for diagnostic purposes.