Which of the following is NOT a step in conventional tissue processing?

The process of conventional tissue processing typically involves several key steps: fixation, dehydration, clearing, embedding, and staining. Each of these steps plays a vital role in preparing the tissue sample for microscopic examination.

Freezing, while a technique used in some contexts (such as frozen section analysis for rapid diagnosis during surgeries), is not part of the conventional tissue processing method that emphasizes the embedding of samples in paraffin wax. This paraffin embedding allows for long-term preservation and easier sectioning of tissue samples.

Embedding involves infiltrating the tissue with a medium (such as paraffin) that solidifies, allowing thin sections to be cut for histological examination. Decalcification, on the other hand, is a step used when dealing with calcified tissues (such as bone) to remove calcium deposits to facilitate easier sectioning. Staining is essential for highlighting different cellular components and facilitating diagnosis by providing contrast in the tissue sections.

In conclusion, freezing is not a standard step in conventional tissue processing, which is why it is the correct answer in this context.