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AAT Bioquest

What is secondary antibody cross reactivity?

Posted September 29, 2021


Answer

Secondary antibody cross reactivity occurs when an antibody raised against one specific antigen successfully binds with a different antigen.

A secondary antibody has a distinct amino acid sequence that influences its affinity for a specific antigen. Cross reactivity occurs when the secondary antibody recognizes two different antigens with similar three-dimensional structural regions or epitopes.

Cross-reactivity can produce inaccurate results and compromise the scientific reproducibility of an experiment. To avoid this, it is crucial to test the secondary antibody for cross-reactivity with closely related proteins before starting an experiment. The cross-adsorption of secondary antibodies can help to prevent cross-reactivity.

Additional resources

Cross-reactive and pre-existing antibodies to therapeutic antibodies—Effects on treatment and immunogenicity

XFD350 goat anti-mouse IgG (H+L) *Cross Adsorbed, XFD350 Same Structure to Alexa Fluor™ 350*