the average particle diameter was approximately 3 microns most of the fluorescence spectra are similar to the single shot spectra labeled a in the inset to fig3 b these have a broad emission from about 300 to 600 nm the more smooth line in a overlapping the single shot result shows the average spectrum of the 100 consecutive single shots the spectra labeled b and c in fig3 b show the 4th and 48th fluorescence spectra from the series of 100 single shots these are distinctly different from the other spectra the 4th spectrum curve c has a band with two peaks located near 320 nm and a broader band that peaks around 450 nm the 48th spectrum curve b has its strongest emission closer to 350 nm chicken house dusts are complicated with a large variety of microbes mixed in a background of organic inorganic and biological matter in the sample measured here the total culturable microbial component is only 1 of the weight and the culturable fungal species make up less than 0 006 of the weight the dominant bacterial species are staphylococcus aureus and brevibacterium the uniformity of the large majority of the spectra in fig3 a suggests that the major fluorescing component of these particles is either soluble or is in the form of very small particulates so that the fluorophors are distributed somewhat uniformly in the suspension used in the ijag the fact that the 4th and 48 th spectra exhibit much larger and spectrally distinct fluorescence suggests that some of the fluorescing material is not uniformly dispersed in the suspension the.