OSMT (Ontario Society of Medical Technologists) Practice Exam

What occurs during the clearing stage of tissue processing?

1. a. Is an intermediate step between alcohols and paraffin

2. b. Is an intermediate step between dehydrating reagents and embedding media

3. c. Can be done with xylene, toluene, chloroform or benzene

4. d. All of the above

The correct answer is: d. All of the above

During the clearing stage of tissue processing, a critical phase occurs where the dehydrated tissues are prepared for embedding in paraffin or other media. This step serves as a transition between the dehydrating agents, like alcohols, and the embedding medium. The use of various clearing agents such as xylene, toluene, chloroform, or benzene is significant, as these substances help to remove the dehydrating agents and replace them with a non-aqueous solvent that allows better infiltration of the embedding medium. This ensures that the tissue samples maintain their structure and integrity during the embedding process, which is vital for subsequent sectioning and histological analysis. Thus, all the stated aspects in the choices accurately describe the clearing stage, making the comprehensive answer valid. Each component contributes to a holistic understanding of the clearing process, emphasizing its importance in the overall tissue processing workflow.