BD23

Biological Aerosol Particle Identification By FCM.

G. Salzman*, G. Saunders, J. Martin, C. Lemanski, J. Parson, M. Naivar, R. Ross, G. Mark, W. Bentley, T. Lobb, C. Briles, K. Braithwaite, R. Smith, M. Sweet, S. Wilson, D. Beck, D. Neagley, J. Bradley, and K. Albright. Los Alamos National Laboratory, Los Alamos, New Mexico.

Fluorescent flow cytometric immunoassays have been developed to identify spores of B. subtilis var. niger, Erwinia herbicola, MS-2 phage, and ovalbumin collected from biological aerosol clouds disseminated during a recent field trial at the U.S. Army Dugway Proving Ground. The two bacteria were directly labeled. The MS-2 phage label used a dual-bead assay method (2.8 µm nonfluorescent beads and 0.1 µm fluorescent beads) and the ovalbumin was a single bead assay (2.8 µm nonfluorescent beads). A Bio-Rad Bryte HS flow cytometer with blue Xenon arc lamp illumination and a FITC fluorescence detection filter block was used for the field test.

Aerosol releases were at night with wind velocities of 1 to 5 m/sec. Aerosol collectors deposited 1000 l/min. of aerosol into 0.5 ml of water. The method was successful in identifying target populations at concentrations of 1000 particles/ml. in the presence of high natural backgrounds. The work was supported by the U.S. Army Chemical and Biological Defense Command at Aberdeen Proving Ground, Maryland.