Measurement by ELISA of Active Lectin in Dietary Supplements Containing Kidney Bean Protein

We describe an ELISA assay to measure the active lectin content in dietary supplements containing protein extracts from Phaseolus vulgaris. Phytohemagglutinin (PHA) is known to induce serious consequences for metabolism and health when consumed raw or only lightly cooked. The ELISA was performed using plates preliminarily coated with porcine thyroglobulin, which has high specificity binding to active lectin. The bound active lectin was detected by a rabbit anti‐PHA IgG and a secondary antibody enzyme conjugate. An assessment of linearity and analytical range were also performed. The data obtained showed good repeatability, specificity and a limit of quantification of 15 ng of PHA. The sensitivity of the method corresponds to 30 ppm.