Glycerol: Properties and Applications

What is glycerol and how is it produced?

Glycerol, also known as glycerin, is a simple polyol compound with the chemical formula C₃H₈O₃. It is a by-product of biodiesel production and can also be derived from animal fats or plant oils through saponification. In the UK, it is regulated under the European Pharmacopoeia (EP) and is listed in the British Pharmacopoeia (BP) as a pharmaceutical excipient. Its high solubility in water and low toxicity make it suitable for use in food, cosmetics, and pharmaceutical formulations.

How is glycerol used in biotechnology and lab workflows?

In laboratory and biotech applications, glycerol is commonly used as a cryoprotectant to preserve microbial cultures, enzymes, and cell lines at ultra-low temperatures (e.g., -80 °C). It prevents ice crystal formation, reducing cellular damage during freezing and thawing. It is also used in protein storage buffers and as a component in electrophoresis gels (e.g., in SDS-PAGE) to improve resolution. Additionally, glycerol serves as a solvent and stabiliser in enzyme assays and diagnostic reagents.

What safety and regulatory considerations apply?

Glycerol is generally recognised as safe (GRAS) by the FDA and is compliant with EU regulations under REACH and GHS. It is non-toxic and non-irritating at typical concentrations. However, high concentrations may cause osmotic effects in biological systems. Suppliers must provide a Certificate of Analysis (CoA) and Safety Data Sheet (SDS), with purity typically ≥99% (USP/BP/EP grade) for lab and pharmaceutical use.

Related concepts

Glycerol is closely related to other polyols such as propylene glycol and ethylene glycol. It is also a key intermediate in metabolic pathways, including glycolysis and lipid metabolism. In bioprocessing, it is monitored in fermentation broths due to its role as a by-product of lipid synthesis.