LIMULUS LYSATE TURBIDITY TEST FOR PYROGENS

摘要

A sample of an aqueous liquid, e.g. an aqueous parenterallyadministered drug, is tested for determining the amount of any endotoxin contained therein by admixing a sample of the liquid with lysate obtained by water lysing washed amebocyte cells from the blood of the horseshoe crab (Limulus polyphemus), said lysate being buffered at a pH between about 6.5 and about 6.8 and being at a concentration such that 1 ml thereof is reactive with 0.1 ml of an endotoxin solution containing 1 ng per ml of endotoxin to develop upon incubation for 60 minutes at 37.degree.C turbidity exhibiting absorbancy between about 0.07 and about 0.2 at 360 nm, incubating the resulting admixture under temperature and time conditions conducive to increase in absorbancy resulting from reaction between said lysate and any endotoxin contained in the sample and determining the absorbancy of the resulting admixture ordinarily in relation to the absorbancy similarly obtained by reaction of the same lysate with one or more solutions of known endotoxin content, whereby the endotoxin content of the sample may be determined not only qualitatively but also quantitatively. In ordinary practice, a buffer which provides a pH of from about 6.5 to about 6.8 when said lysate is at the aforesaid concentration is included in the quantity of lysate in a more concentrated form followed by lyophilization and the buffered lyophilized lysate is reconstituted with water to provide the aforesaid concentration prior to admixture of the sample with the reconstituted solution. Improved stability of the lyophilized buffered lysate is afforded by the presence of "pipes" buffer.