In order to further identify the sialic acid linkages required for PSaV attachment and infection, LLC-PK cells were pretreated with specific lectins to block each specific isoform of sialic acid: 1) 400 μg Maackia amurensis lectin (MAL) ml−1, which binds preferentially to α2,3-linked sialic acid, and 2) 400 μg Sambucus nigra lectin (SNL) ml−1, which binds preferentially to α2,6-linked sialic acid [4]. This evidence concerns the gene MAL and infection.