The processing and collaborative assay of a reference endotoxin

• Published in: Journal of biological standardization Vol. 11; no. 4; pp. 251 - 260
• Main Authors: Hochstein, H.D., Mills, D.F., Outschoorn, A.S., Rastogi, S.C.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Science (USA) 01.01.1983; Academic Press
• Subjects: Animals; Bacteriology; Biological and medical sciences; Chemical Phenomena; Chemistry; Endotoxins - analysis; Endotoxins - standards; Endotoxins - toxicity; Escherichia coli - metabolism; Fever - chemically induced; Fundamental and applied biological sciences. Psychology; Limulus Test; Microbiology; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Reference Standards; Freeze drying; Statistical analysis; Stability; Escherichia coli; Multicenter study; Standard; Endotoxin; Biological activity; Biological preparation; Toxin; Unit of measurement; Preparation; Bacteria
• ISSN: 0092-1157
• DOI: 10.1016/S0092-1157(83)80013-4

A preparation of Escherichia coli bacterial endotoxin, the latest of successive lots drawn from bulk material which has been studied in laboratory tests and in animals and humans for suitability as a reference endotoxin, has been filled and lyophilized in a large number of vials. Details of its characterization, including stability studies, are given. A collaborative assay was conducted by 14 laboratories using gelation end-points with Limulus amebocyte lysates. Approximate continuity of the unit of potency with the existing national unit was achieved. The lot was made from the single final bulk but had to be freeze-dried in five sublimators. An assessment was therefore made for possible heterogeneity. The results indicate that the lot can be used as a large homogeneous quantity. The advantages of using it widely as a standard for endotoxins are discussed.