Entamoeba ELISA

The Entamoeba ELISA uses specific antibodies in a sandwich-type method. The well surface of the microwell plate is coated with specific antibodies to the antigens of Entamoeba histolytica and Entamoeba dispar. A pipette is used to place a suspension of the stool sample to be examined as well as control samples into the well of the microwell plate together with biotinylated anti-Entamoeba antibodies (Conjugate 1) for incubation at room temperature (20 - 25 °C). After a wash step, streptavidin poly-peroxidase conjugate (Conjugate 2) is added, and it is incubated again at room temperature (20 - 25 °C). With the presence of Entamoeba antigens in a sample, immobilized antibodies, the Entamoeba antigen, and the conjugated antibody form a sandwich complex. Another wash step removes the unattached streptavidin poly-peroxidase conjugate. After adding the substrate, the attached enzyme changes the color of the previously colorless solution in the wells of the microplate to blue if the test is positive. Addition of a stop reagent changes the color from blue to yellow. The extinction is proportional to the concentration of Entamoeba antigens in the sample.