Dual fluorescent halogen immunoassay for bioaerosols using confocal microscopy

Abstract

The need to measure bioaerosols has increased dramati-cally in recent years due to the growing incidence of respi-ratory diseases. Fungi are among the most commonbioaerosols that humans inhale and exposure to fungi indomestic and occupational environments has been associ-ated with adverse health eVects such as infections, allergies,mycotoxicoses, or irritations [1]. Numerous fungal speciesare known to produce virulence factors, mycotoxins, andallergens, but many of the fungi that occur naturally in theenvironment remain uncharacterized. This is partly due tothe tremendous diversity of fungal species in the environ-ment, the current lack of analytical methods for the detec-tion and characterization of fungal exposures, and theabsence of standardized fungal extracts for the develop-ment of immunodiagnostic assays.Many strategies have evolved to sample, identify, andinterpret fungal exposure; however, no strategy serves allpurposes, as exposure is a complex and dynamic processconfounded by spatial, temporal, and geographic variationsin airborne counts. Current techniques for fungal exposureassessment rely on sample cultivation or volumetric airsampling in combination with light microscopy [2]. How-ever, these techniques are often time consuming and subjec-tive and require mycological expertise. More recently,molecular techniques based on PCR and immunoassayshave been developed to overcome some of these limitations,although the quantiWcation of viable fungal particles stillremains a challenge [2].In our earlier work [3], we described the development ofan enzyme-based halogen immunoassay (HIA).