The Fab portion of the antibodies made against epitopes of the binding site of an exotoxin blocks the exotoxin from binding to the host cell membrane. As a result, the toxin can not enter the cell and cause harm.

Flash animation illustrating Neutralization of Exotoxins By Antibody Molecules .swf by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at http://faculty.ccbcmd.edu/~gkaiser/index.html.

Last updated: August, 2019
Please send comments and inquiries to Dr. Gary Kaiser