Rapid detection of Salmonella typhimurium using an immunoelectrochemical method coupled with immunomagnetic separation

by Che, Yi Hua; Yang, Zhongping; Li, Yanbin; Paul, David W.; Slavik, Michael F.

An immunoelectrochemical method coupled with magnetic separation was developed for rapid detection of Salmonella typhimurium. Samples containing Salmonella were mired with anti-Salmonella coated magnetic beads (ASCMB) and alkaline phosphatase labeled anti-Salmonella (APLAS) simultaneously to form ASCMB-Salmonella-APLAS conjugates by antibody-antigen reaction. The conjugates were separated by a magnetic field and were incubated with phenyl phosphate substrate to produce phenol. The number of Salmonella was determined by measuring the phenol concentration using an amperometric tyrosinase biosensor. This method could be completed within two hours with a detection limit of 5 x 10(3) cells/mL under optimized conditions (with 1 mM MgCl2, 0.2 mu g/mL APLAS and 1 mM phenylphosphate in pH 7.0 TBS). A linear response on semi-log scale was found for Salmonella pure culture between 5 x 10(3) and 1 x 10(6) ceIls/mL.

Journal
Journal of Rapid Methods and Automation in Microbiology
Volume
7
Issue
1
Year
1999
Start Page
47
ISBN/ISSN
1745-4565; 1060-3999
DOI
10.1111/j.1745-4581.1999.tb00371.x