Modification of the Limulus amebocyte lysate assay for the analysis of glucan in indoor environments

Abstract

beta-1,3- D-Glucan is a biologically active component mainly from fungi that has been shown in several studies to be related to respiratory health outcomes from damp building exposures. Here, we report the development and application of a method for the analysis of the glucan extracted in 0.5 N NaOH solution making use of an available preparation of Limulus amebocyte lysate (LAL). The method yields reproducible beta-1,3- D-glucan measurements from samples of outdoor air, yeast cells, fungal spore preparations and ragweed pollen, and is more sensitive than competing measurements. The LAL-based measurement compared favourably to that based on size-exclusion chromatography using UV and refractive index detection. Growth conditions of the fungi did not materially change the concentrations of glucan in spores indicating that this is a stable property. Glucan content was proportional to spore surface area; however, some species contain higher relative spore glucan contents.

Characterization of Ambient PM10 Bioaerosols in a California Agricultural Town

“…Average (1→3)-β-D-glucan content was 0.16 ± 0.10 pg/spore, within the range of 0.04-3.1 pg/spore found by Foto et al (2004). The average (1→3)-β-D-glucan coating depends on the spore's surface area.…”

“…The average (1→3)-β-D-glucan coating depends on the spore's surface area. The 0.0020 ± 0.0013 pg/µm 2 for Corcoran samples is at the lower end of the 0.00268-0.0598 pg/µm 2 range reported by Foto et al (2004), probably due to the presence of different fungal species.…”

“…(1→3)-β-D-glucan has also been found in some bacteria and most higherorder plants (Rylander, 1999). Foto et al (2004) reported high (1→3)-β-D-glucan content in ragweed pollens (83.0 ± 5.6 ng/mg). Arabitol and mannitol are also found in bacteria and lower-order plants.…”

β-(1,3)-Glucan Exposure Assessment by Passive Airborne Dust Sampling and New Sensitive Immunoassays

“…Even in environments with high microbial contaminations, like the household waste recycling industry (36), ␤-(1,3)-glucan levels in airborne dust samples may often remain under the limit of detection. Until recently, the only published methods sensitive enough to measure ␤-(1,3)-glucans in airborne dust samples were the modified Limulus amebocyte lysate (LAL) assay (a modification of the endotoxin assay with which glucans can be specifically detected [11]) and two sandwich enzyme immunoassays (EIAs) (2,23,27). Due to its high cost, which is at least 5-fold higher than that of the inhibition EIA, the LAL assay has thus far hardly been used in epidemiological studies.…”

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

“…Therefore, information on the content and structure of (1-3)--D-glucan in common indoor fungal species will help in better understanding the health effects associated with these fungi. While there are some data on the content of (1-3)--Dglucans in spores of the indoor fungal species of Penicillium, Aspergillus, Cladosporium and Stachybotrys [23,30], analyzed by the LAL assay, very little is known on the EIAanalyzed (1-3)--D-glucan of spores from different species. LAL-analyzed (1-3)--D-glucan is a recognized indicator of fungal biomass based on health effects and correlation with total fungal count [18][19][20][21].…”