Development of Sampling Methods for Powders and Soil for Detection of Biothreat Agents by Electrochemiluminecence

Abstract : The M1M (BioVeris Corporation), an automated electrochemiluminscent (ECL) assay instrument, has been shown to be a technology that is robust and tolerant of samples in a variety of complex matrices; however, methods for sampling of powders and soils in the field for processing on the M1M have not been described. This report describes the development of simple and reproducible methods that may be used for field sampling of powders and soils for subsequent screening and analysis on the M1M. By sampling with polyester swabs using a standard method, it was found that it was possible to collect a reproducible amount (~l2 mg) of powder or soil from a variety of surfaces. Using this value, the volume of diluent required to produce a signal <1.2 on the M1M was empirically determined. The powder or soil suspension was filtered and the filtrate assayed on the M1M. The result was a method that could be used consistently to assay powder and soil by ECL M1M with good sensitivity and minimal background signal.