Herbert Skip Brown, M. Div. HT(ASCP) Lab Storage Systems, Inc.

Natural or organic wax has a recorded history that dates back to ancient Egyptian culture. Beeswax was discovered and used by the Egyptians as far back as 4200 B.C. \as part of their embalming process. Mummies were wrapped in cloth linen dipped in Beeswax, and the coffins were sealed with the wax. Sculptured portraits of the deceased were modeled in wax form and painted with pigmented Beeswax. The study of this specific kind of wax shows that it was secreted by glands in the honeybee, and used in structuring the honeycomb. It was then melted down in boiling water with the crude wax being skimmed off and refined. For centuries this was the major product used in candles by the Greeks, the Romans, and world-wide by the Roman Catholic Church until the discovery and refinement of paraffin wax. It was later found to be an excellent infiltrate for Histology.

The term ‘wax’ is derived from the Anglo-Saxon word, ‘weax’, which at that time referred to Beeswax. The name became synonymous with similar substances found in plants and the name progressively transitioned from weax, to wachs, to wax. Wax was eventually found in other substances and classified in one of four categories: animal, vegetable (plants), mineral (fossil), and petroleum. The history of paraffin as a histology grade infiltration medium first transitioned from the use of other substances such as celloidin, carbowax, gelatin, and agar; but none proved to be as successful for universal application as paraffin. In 1836 paraffin was produced from crude petroleum oil, with the first refinery opening in 1850. It was first used as an infiltration medium in histology in 1869. Paraffin is a mixture of simple straight chain hydro-carbons. In perfecting the efficiency of paraffin as a sectioning agent in microtomy, researchers began experimenting with adding certain polymers and additives to give it greater strength yet allowing thinner sections to be produced. This of course increased the size of the paraffin molecule but as mentioned allowed micro-sectioning as thin as 3 microns.

Manufacturers began developing their own special proprietary blends of paraffin and wax additives such as polymers, plastics, resins, and micro-crystalline wax. Each company had their own manufacturing process, but it mainly started from getting the raw paraffin wax in one of two forms: either in block wax sheets or shipped in molten form via heated tankers. The key to success was not only in the additive recipe, but in the mixing process as well. Companies realized that it took a calculated and specific amount of time in mixing for the polymers or additives to blend and attach to the paraffin molecules. Early attempts to speed up production by heating at higher temperatures proved to be disastrous as polymers and additives separated out when paraffin was stored for prolonged periods of time before use; as in with the paraffin storage dispensers.

Paraffin wax has certainly gone through an evolutionary period, mainly driven by the voice of the customer, the Histotechnologist. For the sake of patient care, companies are committed to continually refine and develop paraffin wax as an infiltrating medium and sectioning agent so that you have the tools you need to provide the best quality care.

Lab Storage Systems has the products and solutions to ensure your success in tissue infiltration and microtomy. For information on products, techniques, and troubleshooting, contact our Technical Marketing Specialist today.