IMPROVED INVITRO PYROGEN TEST - TO DETECT PICOGRAMS OF ENDOTOXIN CONTAMINATION IN INTRAVENOUS FLUIDS USING LIMULUS AMEBOCYTE LYSATE

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  • 1 January 1977
    • journal article
    • research article
    • Vol. 89  (4) , 910-918
Abstract
A method for in vitro pyrogen testing using Limulus [polyphemus] amoebocyte lysate (LAL) is described. The method is based upon the measurement of endotoxin-precipitable protein and can be used to measure picogram quantities equivalent to Escherichia coli endotoxin in unknown solutions. When increasing concentrations of E. coli endotoxin are added to a constant amount of LAL and the reaction is allowed to proceed to completion, there is a proportional increase in the protein precipitated by endotoxin. Therefore, by measuring the amount of protein precipitated from LAL, it is possible to determine the equivalent E. coli endotoxin concentration in unknown solutions, when samples of the unknowns are run simultaneously with E. coli endotoxin standards and negative controls. The endotoxin proportional precipitation of protein occurs in reaction mixtures showing gelation and in reaction mixtures where the endotoxin levels are lower than required for gelation. Determination of precipitated protein provides greater sensitivity for endotoxin detection than the gelation methods currently in use.