TY - JOUR
T1 - Measurement of Bound and Free Endotoxin by the Limulus Assay (38240)
AU - Jorgensen, James H.
AU - Smith, Rodney F.
PY - 1974/9
Y1 - 1974/9
N2 - The Limulus assay was used to measure activities of naturally occurring and chemically extracted endotoxins and endotoxin fractions. Large amounts of both bound and free endotoxin were detected from gram-negative bacterial cells grown in either enriched or minimal media, and from resting cells. Following purification by phenol extraction, free endotoxin evidenced a similar level of activity to that of bound endotoxin. Lipid A and polysaccharide prepared by hydrolysis of endotoxin demonstrated reduced Limulus activity. However, R-strains from three species of gram-negative bacilli produced large amounts of free endotoxin. These results indicate that free endotoxin is part of the LPS that is readily released in a liquid environment, and probably is composed of lipid A and core material. In addition, a relatively constant amount of endotoxin remains bound on the cell surface, allowing an approximate quantitation of viable bacilli in fluids using the Limulus assay.
AB - The Limulus assay was used to measure activities of naturally occurring and chemically extracted endotoxins and endotoxin fractions. Large amounts of both bound and free endotoxin were detected from gram-negative bacterial cells grown in either enriched or minimal media, and from resting cells. Following purification by phenol extraction, free endotoxin evidenced a similar level of activity to that of bound endotoxin. Lipid A and polysaccharide prepared by hydrolysis of endotoxin demonstrated reduced Limulus activity. However, R-strains from three species of gram-negative bacilli produced large amounts of free endotoxin. These results indicate that free endotoxin is part of the LPS that is readily released in a liquid environment, and probably is composed of lipid A and core material. In addition, a relatively constant amount of endotoxin remains bound on the cell surface, allowing an approximate quantitation of viable bacilli in fluids using the Limulus assay.
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U2 - 10.3181/00379727-146-38240
DO - 10.3181/00379727-146-38240
M3 - Article
C2 - 4214493
AN - SCOPUS:0016176263
SN - 1535-3702
VL - 146
SP - 1024
EP - 1031
JO - Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N. Y.)
JF - Proceedings of the Society for Experimental Biology and Medicine. Society for Experimental Biology and Medicine (New York, N. Y.)
IS - 4
ER -