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LABORATORY INVESTIGATION OF SCANRDI FOR AGENCY ACCEPTANCE.  Kevin Lewis¹, Alex Lugo Valle², Carmen Ramos Cortes³, and Randall Sumner³. ¹Univeristy of Illinois, Urbana-Champaign, ²University of Puerto Rico in Arecibo, ³The Bionetics Corporation, Kennedy Space Center, Florida 32899

     Several traditional methods are used to determine the numbers of bacteria in fluids.  These approaches are time consuming and depend on culturing the bacteria. This project investigated the validity of the nascent methodology of SPLC, which combines laser technology and fluorescence to yield a rapid accurate bacterial cell count without culture lag time.  The determination of a functional timescale of the SPLC technique relative to the pour plate technique was also undertaken; this had not been previously assessed.  This study suggests that the SPLC method, employed by the Chemunex ChemScan RDI, is less sensitive providing a lower approximation of bacterial cell counts.  Moreover, the SPLC bacterial approximations obtained through this study most closely modeled a 48-hour pour plate culture, yet were performed in three hours.  Despite being subject to systematic errors giving only an approximate number of bacteria, the pour plate culture technique in this study yielded higher bacterial counts.  It was expected the SPLC method would avoid culturing errors and provide a more exact bacterial enumeration.