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Updated: Aug 9, 2026
ELIME (Enzyme Linked Immuno Magnetic Electrochemical) Method for Mycotoxin Detection
Published on: October 23, 2009
Immunomagnetic flow cytometric detection of staphylococcal enterotoxin B in raw and dry milk
Takahisa Miyamoto1, Hideaki Kamikado, Hiroshi Kobayashi
1Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, 6-10-1, Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan. tmiyamot@agr.kyushu-u.ac.jp
Insights
A new method uses immunomagnetic separation and flow cytometry to detect staphylococcal enterotoxin B (SEB) in milk. This rapid technique offers sensitive detection of SEB contamination in dairy products.
Area of Science:
- Food Safety
- Analytical Chemistry
- Immunology
Background:
- Staphylococcal enterotoxin B (SEB) is a potent toxin found in food.
- Accurate detection of SEB is crucial for public health and food safety.
Purpose of the Study:
- To develop a rapid and sensitive method for SEB detection in milk.
- To utilize antibody-based immunomagnetic separation (IMS) and flow cytometry (FCM) for SEB analysis.
Main Methods:
- Immobilization of anti-SEB IgG on magnetic beads for capturing SEB.
- Detection of captured SEB using a secondary antibody labeled with Cy5.
- Quantification of SEB by measuring fluorescent beads via flow cytometry.
Main Results:
- The IMS-FCM assay provided distinct peaks for magnetic beads and contaminants.
- Fluorescence intensity and percentage of fluorescent beads correlated with SEB concentration.
- Lower limits of detection were 0.01 ng/ml in buffer and 0.25 ng/ml in milk samples.
Conclusions:
- The developed IMS-FCM method is rapid and sensitive for SEB detection in milk.
- This assay can be valuable for ensuring the safety of dairy products.
- The technique offers a reliable approach for monitoring SEB contamination.
Abstract:
A rapid and sensitive method for detection of staphylococcal enterotoxin B (SEB) in raw and dry milk samples with the use of antibody-based immunomagnetic separation (IMS) in conjunction with flow cytometry (FCM) was developed. Sheep anti-SEB immunoglobulin G (IgG) was immobilized on Dynabeads M-280. The SEB initially binds to the capturing antibody, which is bound on the magnetic beads. The rabbit anti-SEB IgG binds to the captured toxin and is further labeled with a Cy5-labeled goat anti-rabbit IgG antibody. The percentage of the beads that were fluorescent was measured by FCM. FCM was carried out for 1 min, and the data obtained were expressed as histograms for particle size (forward light scatter) and histograms for fluorescence intensity. A peak corresponding to the magnetic beads was clearly distinguished from a peak derived from contaminating particles in the sample solution. In the absence of SEB, about 10% of the beads emitted fluorescence. The percentage of fluorescent beads and the fluorescence intensity increased with increasing SEB concentrations. For this IMS-FCM assay, the lower limits of detection for SEB were estimated to be 0.01 and 0.25 ng/ml for buffer and milk samples, respectively.
