Morus rubra, commonly known as the red mulberry, is a species of mulberry native to eastern and central North America. The red mulberry tree is a small to medium sized undergrowth tree (6 to 20 m high). Its deciduous leaves are polymorphous, alternate, unlobed, bilobed or trilobed, 9 to 24 cm long.

Morus rubra lectin (MRL) is isolated from red mulberry was purified to homogeneity from the leaves by a single-step immobilized metal ion affinity chromatography (IMAC) procedure. The molecular weight of MRL is around 52,000 and has a specificity towards galactose, D-galactosamine and N-acetyl-D-galactosamine. MRL also has haemagglutination activity towards different erythrocyte blood groups. MRL has stability over a wide range of temperatures (up to 80°C) and an isoelectric point that ranges between pH 4 and pH 11. Lectin bonding with EDTA did not alter the haemagglutining activity which demonstrates that metal ions are not required for activity.