ASCP Histotechnician Certification 2025 – 400 Free Practice Questions to Pass the Exam

The correct sequence of major steps involved in processing a tissue sample is fixation, dehydration, clearing, embedding, sectioning, and staining.

Fixation is the first step in tissue processing, which preserves the tissue's structure and composition by preventing autolysis and putrefaction. This is typically achieved using fixatives such as formalin.

Following fixation, the tissue undergoes dehydration to remove water, which is crucial because most embedding media, like paraffin, are not compatible with water. This step is done using a series of alcohol solutions of increasing concentration.

The next step is clearing, where the tissue is treated with a solvent that will remove the alcohol and make the tissue compatible with the embedding medium. Common clearing agents include xylene or toluene.

Embedding comes after clearing; this process involves infiltrating the tissue with a suitable embedding medium, such as paraffin wax, which supports the tissue structure and allows for thin sectioning.

Sectioning is the slicing of the embedded tissue into very thin slices using a microtome, which are then mounted on slides for examination.

Finally, staining enhances the visibility of different components of the tissue under a microscope, making it easier to identify structures and any pathological changes.

This comprehensive sequence ensures that the