The effect of extraction, storage, and analysis techniques on the measurement of airborne endotoxin from a large dairy

Dungan, R.S. and Leytem, A.B. (2009) The effect of extraction, storage, and analysis techniques on the measurement of airborne endotoxin from a large dairy. Aerobiologia. 25:265-273.

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Abstract

The objective of this study was to fill in
additional knowledge gaps with respect to the
extraction, storage, and analysis of airborne endotoxin,
with a specific focus on samples from a dairy
production facility. We utilized polycarbonate filters
to collect total airborne endotoxins, sonication as the
extraction technique, and 0.05% Tween 20 in pyrogen-
free water (PFW) as the extraction solution.
Endotoxin concentrations were determined via the
Limulus amebocyte lysate (LAL) assay. The endotoxin
concentrations in extracts after 15 and 30 min
of filter sonication were similar, while the concentration
in 60 min extracts was about twofold lower.
Rapidly vortexing samples for up to 15 min after
sonication did not increase the endotoxin concentration.
However, concentrations were 13 and 26%
lower in extracts that were centrifuged at 1,000 and
10,000g for up to 15 min, respectively. Field samples
and endotoxin standard were also sonicated in glass
or polypropylene tubes for up to 120 min. Regardless
of the extraction vessel, a decrease in endotoxin
concentration occurred when sonicated for[30 min.
Samples and endotoxin standard subjected to 12
freeze–thaw cycles at -20�C only showed a slight
but not significant decrease in endotoxin concentration.
Our results also demonstrate the importance of
simultaneously adding LAL reagent to 96-well plates
before initiating the LAL assay.

Item Type:	Article
NWISRL Publication Number:	1324
Subjects:	Manure Animal
Depositing User:	Users 6 not found.
Date Deposited:	30 Nov 2009 22:28
Last Modified:	14 Oct 2016 14:56
Item ID:	1347
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/1347