This system can utilize various enrichment media to provide E. coli O157:H7 with readily available nutrients and other factors required for its survival and rapid growth. Used with Reveal® media, the system can provide results within 8 or 20 hours for 25 g samples, or results within 12 or 20 hours for 375 g samples.

A portion (120 µL) of the enrichment culture is placed into the round sample port of the Reveal test device. This sample is wicked through a reagent zone that contains specific antibodies (anti-E. coli O157:H7) conjugated to colloidal gold particles. If target antigens are present in the sample, they will bind to the gold-conjugated antibodies. This antigen-antibody complex then leaves the reagent zone and travels through the nitrocellulose membrane that contains a zone of anti-E. coli O157:H7 antibody. The immune complex with gold conjugate is captured and aggregates in this zone, thus displaying a visible line. The remainder of the sample continues to migrate to the end of the membrane where it will eventually become deposited into a waste reservoir.

The reagent zone also contains gold conjugate of a proprietary antigen (color indicator), which is eluted by the sample solution regardless of the presence of E. coli O157:H7 antigen. The gold-conjugated control indicator migrates through the membrane to the negative control capture zone (antibody to the proprietary antigen), where it is captured and aggregated to form a visible line. Regardless of the presence or absence of the E. coli O157:H7 antigen, the control line will form in the control zone, ensuring the test is working properly.