Beans of high or low toxicity

Extracts of seeds from four bean cultivars representing the four hemagglutinin specifity types were injected into mice. The lethal doses LD₅₀ when injected by the intraperitoneal route were for type A; 470 mg/kg, type B; 1500 mg/kg, type C; 590 mg/kg, and type D; >3000 mg/kg calculated as injected bean protein per kg of body weight. When applied intravenously the D-type extract resulted also the less toxic. Intradermal injections of the four extracts produced local lesions which were most severe with the A-type extracts and very light with the D-type extracts. The genetical selection of the non-toxic D-type beans is recommended.