ABSTRACT
This chapter focuses on discussing important considerations regarding this interesting molecule. Lipopolysaccharides (LPS) or endotoxins are pyrogenic contaminants found in microorganisms such as Gram-negative bacteria. LPS are the most common molecules and make up about 75% of the outer membrane of these microorganisms. The chapter discusses the main characteristics and properties of LPS, summarizing some of the aspects of each portion of the molecule. The LPS test in rabbits was first introduced into the United States Pharmacopoeia in 1942. All materials used during the LPS test in rabbits, such as glassware used in the preparation of samples, syringes and needles used for intravenous injection of the tested sample, must be previously depyrogenized. The pyrogen test was developed to limit to an acceptable level the risks of febrile reactions in patients following intravenous administration of a pharmaceutical product. Rabbits were chosen as the test species because the thermoregulatory system of these animals most closely resembled humans.
