An Avidin-Biotin Conjugation Technique for Presenting Target Antigens on Mycobacterium bovis BCG

Abstract

Source: Liao, T. A., et al., Expression of Exogenous Antigens in the Mycobacterium bovis BCG Vaccine via Non-genetic Surface Decoration with the Avidin-biotin System. J. Vis. Exp. (2018).

The video demonstrates a technique for loading antigens on Mycobacterium bovis BCG to improve its immunogenic properties. The method uses the avidin-biotin system to coat the bacterial surface with exogenous antigens.

Protocol

1. Biotinylation of BCG Cell Surface

1. Grow BCG in Middlebrook 7H9 broth with 10% OADC (oleic acid, albumin and dextrose solution) and 0.05% Tween 80 at 37 °C on a shaker platform at 50 rpm until OD = 0.5-1.
   NOTE: BCG is a biosafety level 2 pathogen and all experiments concerning BCG should be done in a biosafety cabinet with proper personal protective equipment.
2. Wash 10⁹ BCG 3 times with 500 µL of ice-cold endotoxin free PBS plus 0.1% Tween80 (PBST) (pH 8.0). Suspend BCG pellet in sterile endotoxin free PBS.
3. Immediately before use, prepare 1 mL of 10 mM Sulfo-NHS SS bi....

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Endotoxin-free RPMI 1640	StemCell Technologies	36750
Sulfo-NHS SS biotin	Thermo Fisher	21328
Middlebrook 7H9 broth	BD Diagnostic Systems	271310
OADC	BD Diagnostic Systems	B11886
Tween 80	Sigma-Aldrich	P1379