Novel endotoxin assay by laser light‐scattering particle‐counting method

摘要

Exposure of amoebocyte lysate to endotoxin under stirring produced light‐reflective particles that appeared to be coagulin polymers. A laser light‐scattering particle counter, the PA‐200, detected these particles sensitively. The PA‐200 detected endotoxin at a concentration as low as 0.00015 EU/ml in 71 min, whereas the minimum endotoxin concentration measured by a turbidimeter, ET‐2000, was 0.0005 EU/ml in 138 min. Moreover, PA‐200 was much less affected by the presence of colored substances and refractive materials than was ET‐2000. We propose that the high sensitivity, speed, and high interference tolerance of the laser light‐scattering particle‐counting method make it more useful than the widely used turbidimetric method for quantitative endotoxin assay. J. Clin. Lab. Anal. 23:117–124 (2009). © 2009 Wiley‐Liss, Inc.