Pure paraffin wax is found as a white, odorless, tasteless, waxy solid. Its typical melting point, without additives, is between 46° C to 68° C. Manufacturers have improved histology paraffin by improving and refining the purification methods of the basic paraffin wax base. Currently, most commercial histology paraffin is a mixture of the following components:
- Paraffin wax
- Hydrocarbon polymers or resins (increases hardness and support)
- Microcrystalline waxes and/or bees wax (reduces crystal size, regulates melting point, and increases adhesion for ribboning)
- Additive of dimethyl sulphoxide (DMSO), a hygroscopic compound, which improves infiltration of wax into the tissue
There are many different and specialized paraffin formulations available in the current market. There is no one best paraffin for every laboratory or laboratory situation. However, the performance of any paraffin formula is affected by the following variables:
- Melting point: Depends on the molecular weight and proportions of additives
- Degree of polymerization: Related to the amount of stabilization additive
- Working temperature: Maintained during infiltration and embedding
