Detection of carbohydrate binding proteins using magnetic relaxation switches

We have developed a simple, rapid, and sensitive carbohydrate-based magnetic relaxation switch assay for the detection of carbohydrate binding proteins. This technique was used to detect lectins and toxins that are known to bind to specific carbohydrates. Lectins that bind to the same carbohydrate displayed differential aggregation profiles because of differences in the structure and number of binding sites of the lectins. We demonstrated that selectivity and sensitivity can be enhanced using two different recognition elements. We have also demonstrated that magnetic relaxation switch assays can be used to detect toxins in a complex medium such as stool and environmental samples.