SDS-PAGE (a) and Western immunoblot (b) of Alpha-1 Antitrypsin Select (GE Healthcare, Pittsburgh, PA) chromatography for plant recombinant AAT samples. M – molecular weight marker; C – Analytical standard human AAT (Calbiochem,EMD Millipore, Billerica, MA ); P – Prolastin-C® (Grifols, Barcelona, Spain); FT – Unbound protein from collected flowthrough; E – eluted protein. The band for prAAT appears at a lower molecular weight than both bands for human AAT due to differing glycosylation patterns.