Polarized light micrograph of polyethylene glycol (PEG) crystals. It constitutes a bioinert compound, with many applications in medicine as a laxative, an anti-ulcer agent, and in nerve repair. It also exhibits excitant, anesthetic, and anti-microbial functions. In biological chemistry is used to precipitate proteins, viruses, DNA, and RNA. It is also utilized in encapsulated cell therapy, and as a tissue-regenerating material. As a biomaterial it is used for implantable prostheses, and is among the most common polymer?ased nanoparticles, e.g., coupling PEG to various chemotherapeutic drugs such as Taxol to generate novel nanoparticles for cancer therapy. It is the basis of skin creams and an excipient in many pharmaceutical products. PEG is also employed to de-ice aircraft and airport runways, in petroleum and lubricant production, etc. Field of view size: 5.88 x 8.83 mm (0.232 x 0.347 in)