Analysis, under reducing conditions, of purified 2G12. 2G12 and antibody fragments from plant extracts were purified using Protein A/G affinity chromatography. Samples were reduced and separated by SDS-PAGE. In Panel A, separated proteins (15% gel) were detected with Coomassie staining. The positive control (PC) consists of 500 ng/lane of human IgG1κ. The positions of free heavy and light chains are indicated by H and L, respectively. In Panels B and C, separated proteins (4-15% gradient gels) were blotted to nitrocellulose membranes and probed with either human Fc-specific antiserum (Panel B) or anti-kappa antiserum (Panel C). The positions of the free heavy (H) and light (L) chains are indicated, while the lower molecular weight species labelled a to e indicate antibody fragments.