What is the melting point range of soft wax?

• A. 35-40
• B. 45-50
• C. 50-60
• D. 60-70

Answer: (B)

The melting point range of soft wax reflects how easily it can be melted for embedding and then solidify to support tissue during sectioning, while still protecting delicate structures from heat. Soft wax is formulated to melt at a moderate temperature—low enough to minimize heat exposure to tissue, but high enough to maintain shape when cooled. That balance is typically around 45-50°C, which lets you warm the wax to infiltrate and embed without risking damage from higher heat, yet still provides solid support once cooled for precise microtomy.

If the melting point were as low as 35-40°C, the wax would become too soft with even mild warming or handling, leading to deformation of tissue blocks. If it were in the 60-70°C range, the wax would be too hard, increasing the risk of heat-related artifacts and making embedding and trimming more difficult. Therefore, 45-50°C is the most appropriate range for soft wax.