Abstract: To develop and test its performance of colloidal gold immunochromatographic test strip for rapid detection of Enterobacter sakazakii（ES）. The colloidal gold particles were prepared by the sodium citrate reduction method. Purified ES monoclonal antibodies were labelled with the colloidal gold particles. The gold-labeled antibody was coated on the gold conjugate pad using the immune double sandwich method. The another mAb of ES was coated on the surface of nitrocellulose filter membrane（NC）as the test line（T line）, while the secondary antibody（goat anti-rabbit IgG antibody）was coated on the surface of NC as the control line（C line）. Then the test strip was assembled with sample pad, absorbing pad, and dorsal shield. Its sensitivity, specificity, stablility and reproducibility were evaluated. It can detect the sample content of ES by means of a simple enrichment process. This whole time will take 6 h. The test strip’s sensitivity reached 1×104 CFU/mL, and displayed perfect specificity without cross reactions with food-borne pathogens. All these results showed that the strip was simple, sensitive, specific, stable, and rapid for detection of ES.

Key words: Enterobacter sakazakii, Monoclonal antibody, Colloidal gold, Rapid detection