ALN has a differential ability to bind to erythrocyte cell membranes from different host species. His-ALN (500 ng) or buffer (negative control) was added to erythrocytes, and the mixture was incubated on ice for 20 min. Untreated (no reactivity, data not shown) or ALN-treated erythrocyte membrane fractions from human (H), bovine (B), ovine (O) or rabbit (R) blood were separated by SDS-PAGE, transferred to nitrocellulose, and immunostained with 1/1000 rabbit anti-His-ALN. His-Aln (500 ng) in absence of erythrocyte membrane fractions (ALN) serves as the positive control. Molecular mass markers (kDa) are indicated on the left.