Use of Immunomagnetic Carriers for the Rapid Detection of Virulent Bacteria from Biological Samples
An antibody-based magnetic immunoassay for the effective and rapid detection of virulent bacteria from biological samples was developed. Chemically linked streptavidin-magnetic particles and biotinylated primary antibodies as immunomagnetic carriers were used for bacteria capture. A probe-labeled secondary antibody formed a sandwich for antigen detection. The use of immunomagnetic carriers for bacteria separation is a key step to reduce media interference from biological samples prior to detection. Magnetic separation has been achieved by two types of separators developed in-house. The first is a single channeled flow-through immunomagnetic separator (IMS), the second a multiple-well magnetic plate (MP) separator. An electrochemiluminescence analyzer and a fluorescence plate reader were employed to detect the bacteria. Experiments were performed for virulent Escherichia coli 0157:H7 and Salmonella typhimurium strains, Bacillus anthracis and Bacillus subtilus var. niger (BG) spore detection from different biological samples using both magnetic separators. In general, the detection of the biological samples after magnetic separation was more sensitive and showed lower background levels than the detection without magnetic separation.
KeywordsMagnetic Particle Magnetic Separation Fluorescence Plate Reader Bacterium Detection Virulent Bacterium
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