E.Coli Verotoxin (Fecal) ELISA kit description:

The DAI E. coli Verotoxin Detection ELISA is an in vitro procedure for the qualitative determination of
verotoxin in feces. It is a double antibody (sandwich) ELISA using anti-verotoxin antibodies to capture
the antigen from the stool supernatant. A second anti-verotoxin monoclonal antibody cocktail is then
added, which binds to the complex. This reaction is visualized by the addition of anti-mouse antibodies
conjugated to peroxidase. The resulting blue color following the addition of the chromogen indicates the
presence of verotoxin being bound by the anti-verotoxin antibodies.

The verotoxin (VT), or shiga-like toxin family is a group of closely related toxins produced by certain
strains of Escherichia coli.4 These strains are a significant cause of human hemorrhagic colitic (HC) and
hemolytic uremic syndrome (HUS). In addition, they are both water borne and food borne and may also be transmitted from person-to-person by the oral-fecal route. In adults, illness caused by verotoxin
may last several days, while in children and the elderly, the illness can be fatal. Infections occur as sporadic illnesses or outbreaks, and are distributed throughout North and South America, Europe, and Asia. The peak incidence of infection occurs during summer months.4 In the past, lengthy and cumbersome diagnostic procedures have been utilized for the detection of verotoxin. Currently, simple to perform enzyme-linked immunosorbent assays (ELISA) are being used as an alternative to these longer tedious methods. These antigen-detection assays provide a cost-effective tool for the management of diarrheal disease with an accurate and rapid test.

During the first incubation, verotoxin present in the stool supernatant is captured by antibodies attached to the wells. The second incubation adds an additional anti-verotoxin antibody cocktail that
“sandwiches” the antigen. The next incubation attaches horseradish peroxidase to the sandwich. After
washings to remove unbound enzyme, a chromogen is added which develops a blue color in the presence of the enzyme complex and peroxide. The stop solution ends the reaction and turns the blue color to yellow.