Mouse monoclonal antibodies to health-threatening botulinum neurotoxins (BoNTs) of types A, B, E, and F have been produced and characterized. The antibodies are capable of interacting with a toxin inside the respective natural toxic complex. A sandwich ELISA for the quantitative detection of botulotoxins has been developed on based on the antibodies. The detection limits of the test systems for BoNTs A, B, E, and F is 0.4, 0.5, 0.1, and 2.4 ng/ml, respectively. The assay quantitatively detects BoNTs in canned meat and vegetables. Two antibodies, BNTA-4.1 and BNTA-9.1, both separately and in combination, are capable of neutralizing the natural botulinum toxic complex of type A in vivo; a combination of antibodies neutralizes a higher dose of the toxin. It has been shown that the antibody BNTA-4.1 binds specifically to the light (catalytic) chain of the toxin, and the antibody BNTA-9.1 interacts with the heavy chain. We believe that monoclonal antibodies BNTA-4.1 and BNTA-9.1 hold promise for developing therapeutic antibodies to treat BoNT/A-caused botulism in an emergency. © 2011 Pleiades Publishing, Ltd.