Open AccessDetection of bacterial endotoxin in human tissues
Author(s) -
Jennifer Nalepka,
Edward M. Greenfield
Publication year - 2004
Publication title -
biotechniques/biotechniques
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.617
H-Index - 131
eISSN - 1940-9818
pISSN - 0736-6205
DOI - 10.2144/04373st06
Subject(s) - limulus amebocyte lysate , false positive paradox , lipopolysaccharide , subclinical infection , biology , microbiology and biotechnology , bacteria , limulus , immunology , virology , genetics , paleontology , machine learning , computer science
Detection of bacterial lipopolysaccharide (LPS) in the absence of overt infection is a challenging problem in tissue homogenates and other complex samples. We found that conventional Limulus amebocyte lysate (LAL) assays are not suitable for this purpose due to interference from β-glucan-like molecules. In contrast, a modified LAL assay that is unaffected by β-glucan-like molecules was able to detect LPS in infected tissue and in a subset of clinically aseptic tissues. A two-step LAL assay was used to exclude the possibility of false positives due to nonspecific amidases. False positives due to sample color were also excluded, as were false negatives due to assay inhibition. This is the first report to successfully detect LPS in tissue in the absence of overt infection. This approach may be extremely useful in assessing recent hypotheses that subclinical levels of bacteria contribute to a wide range of chronic diseases.