Comparison of Two Analytical Methods for Detecting (1-3)- -D-Glucan in Pure Fungal Cultures and in Home Dust Samples

There are two methods available for the analysis of (1-3)- -D-glucan: the Limulus Amebocyte Lysate assay (LAL) and the inhibition Enzyme Immunoassay (EIA). The aim of this study was to compare the accuracy and specificity of these two methods in detecting eight alpha and beta-glucan standards, and their sensitivity for the analysis of (1-3)- - D-glucan content of common indoor fungal species and indoor dust samples. The results show that the LAL assay is more accurate, specific, and sensitive in measuring linear and branched  -D-glucans than the EIA. The greatest LAL-analyzed (1-3)-� -D-glucan content per spore (241 pg/spore) was found with E. nigrum, which also had the largest spore size (28 μm). The biomass-normalized (1-3)-� -D-glucan content of fungal spores from pure cultures was within similar range with the two assays but no correlation was found between the results from the two assays. In contrast, there was a significant correlation between the EIA and LAL-measured (1-3)-� -D-glucan concentrations (� g/m 2 of floor area) in field dust sam- ples.