Development of Loop-mediated Isothermal Amplification (LAMP) for Detection of BW10KD Allergen in Buckwheat

Introduction: Buckwheat has been commonly consumed in Asian countries, including Korea and Japan, because it has been recognized as functional food to prevent hypertension and cardiovascular disease. However, BW10KD, a 10 kDa buckwheat protein, is known as one of the major allergenic proteins in buckwheat. The contamination of buckwheat by the allergen has potential to induce serious allergenic reaction in sensitized people. A polymerase chain reaction (PCR) assay to detect the BW10KD gene, which encodes the allergenic proteins of buckwheat was recently developed.

Purpose: Since the ELISA and PCR assays for BW10KD were not sensitive enough to detect buckwheat contamination in food, this study aimed to develop a rapid and reliable loop-mediated isothermal amplification (LAMP) technique for its detection.

Methods: This study developed a BW10KD-specific LAMP detection assay, with high specificity and sensitivity, for use in foods. DNA was extracted from buckwheat, beans, wheat, and rice purchased from wholesale market. The sensitivity and specificity of LAMP and PCR for BW10KD were compared in buckwheat, bean, wheat, and rice DNA.

Results: The sensitivity of LAMP was 10-times higher than PCR. The detection limit of LAMP for BW10KD was as low as 100 pg of buckwheat BW10KD. LAMP developed in this study could specifically detect BW10KD without cross-activity with other food allergen.

Significance: This study concluded that LAMP is a rapid and reliable technique to detect the contamination of buckwheat allergen in foods.