OSMT (Ontario Society of Medical Technologists) Practice Exam

What is the most common form of embedding media used in histology?

1. a. cellulose nitrate

2. b. agar gel

3. c. synthetic resins

4. d. paraffin wax

The correct answer is: d. paraffin wax

The most common form of embedding media used in histology is paraffin wax. Paraffin wax is favored in histological preparations because it provides excellent support for the tissue during slicing, permitting the creation of thin, uniform sections necessary for microscopic examination. The wax solidifies at room temperature and can be cut easily with a microtome, allowing for high-quality diagnostic slides. Paraffin also allows for the preservation of cellular morphology and anatomy, which is crucial for accurate analysis. Its use has become the standard in many laboratories due to its availability, cost-effectiveness, and compatibility with various staining techniques, making it suitable for a wide range of tissues. Other options mentioned, such as cellulose nitrate and synthetic resins, while they can be used for embedding, are less common in routine histological practice compared to paraffin. Agar gel, although useful in some situations, does not provide the same level of support as paraffin wax for the slicing process. Thus, paraffin wax remains the predominant choice for embedding in histology.