Western Blot of Rabbit Anti-HUMAN IgA (alpha chain) Antibody Lane 1: Human IgA Load: 100 ng per lane Primary antibody: HUMAN IgA (alpha chain) Antibody at 1:1000 for 60 min at RT Secondary antibody: DyLight 649 goat anti-rabbit at 1:20,000 for 30 min at RT Block: 5% BLOTTO 30 min at RT Predicted/Observed size: 60and 28 kDa, 60 and 28 kDa