Smart Materials & Structures

Biography

Biography: Shiquan Tao

Abstract

An immunomagnetic separation (IMS) method was developed for separating Salmonella bacteria from large-volume samples of raw eggs. An egg was homogenized with a blender. The homogenized egg material was diluted with a 0.05% Triton X-100 solution to make a 200 mL sample mixture. Anti-Salmonella typhimurium antibody coated magnetic micro particles (MMP) were used to trap Salmonella typhimurium bacteria in the sample mixture. The Salmonella-trapped MMP were separated from the egg sample mixture by using a large magnet. An enzyme-linked immunosorbent assay method was adopted and revised for detecting the bacteria trapped onto the MMP. Horseradish peroxidase labeled anti-Salmonella typhimurium antibody was used to label the trapped bacteria, and a SureblueTM solution was used as a substrate. The color compound resulted from horseradish peroxidase catalyzed reaction was detected with UV/Vis absorption spectrometry using a 1 cm sample cell. This simple method can detect 1.4x107 Salmonella typhimurium cells in one raw egg (7.0*104 Salmonella cells/mL in a sample mixture) without any pre-enrichment. The method is quick, can obtain test results within 5 hours. The results presented in this poster demonstrate the feasibility of using IMS for separating bacteria from large volume complex samples, which could be adopted for detecting bacteria in other type samples in food safety inspection.