The Science Inside: Allergen Sandwich ELISA

July 12, 2019

A look inside the science of Neogen's Allergen Sandwich ELISA test.

Video Transcript

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Allergen Sandwich ELISA

Neogen's food allergen sandwich enzyme-linked immunosorbent assays, or ELISAs, contain antibody-coated wells with antibodies specific to the kit's target substance.

First, the extracted sample is added to the antibody-coated wells.

While the sample incubates, allergen present in the sample binds to the capture antibody.

Following incubation, the well is washed leaving the allergen that has bound itself to the capture antibody.

A conjugate, or antibody detector, is added.

During the second incubation, the conjugate binds to the remaining allergen that is bound to the capture antibody creating the sandwich.

The well is washed again leaving only the conjugate that has bound to the already bound allergen.

A substrate is added and over a set time reacts with the conjugate changing the color of the liquid.

Finally, a stopping solution is added to halt the reaction for interpretation.

A greater amount of allergen present in the well means there is more conjugate which interacts with the substrate creating a darker color.

This indicates a positive result.

Little or no allergen in the well means that less conjugate interacts with the substrate creating less blue color.

This indicates a negative result.

For quantitative results the well's optical densities are read on a microwell reader.

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Category: Science Insights