The purpose of this amendment is to add the following technical specifications to the solicitation requirements.

E. coli O157:
An FL1 fluorescent reagent selective for E. coli O157 that requires only 5 minutes of mixing with a suspension of the target cells in order to properly tag them for flow cytometric detection. The selectivity should be demonstrable with five or more examples of O157 isolates for inclusivity and twenty or more isolates of ordinary E. coli and other similar enterobacter for exclusivity. This reagent must be insensitive with respect to performance in a flow cytometer in the presence of liquids (extracts, washes) associated with three common E. coli-contaminated foods: ground beef, lettuce, and spinach. The reagent should provide signals that also allow the distinction of viable from dead target cells, so that only the viable are enumerated.

Salmonella:
An FL1 fluorescent reagent selective for Salmonella enterica enterica serovars responsible for at least 95% of the U.S. salmonellosis outbreaks in a typical year. The reagent should require only 10 minutes of mixing with a suspension of the target cells in order to properly tag them for flow cytometric detection. The selectivity should be demonstrable with at least 20 isolates to show the required standard of inclusivity and twenty or more isolates of non-target bacteria for exclusivity. This reagent must be insensitive with respect to performance in a flow cytometer in the presence of liquids (extracts, washes) associated with common Salmonella-contaminated foods such as jalapeno peppers. The reagent should provide signals that also allow the distinction of viable from dead target cells, so that only the viable are enumerated.