Figure 3.

Transient expression and purification of cT84.66. (A) Protein extracts from tobacco leaves infiltrated with the light chain (L), the heavy chain (H), and leaves simultaneously infiltrated with both light and heavy chain constructs were analyzed by ELISA using CEA/NA3 as antigen. An in vitro mixture of extracts from leaves infiltrated with only light or heavy chain constructs and noninfiltrated leaf extract were used as controls. Bound antibodies were detected with AP-conjugated GAH-Fc. Bars represent OD₄₀₅ values of 1:64 diluted samples. Protein A affinity purification of recombinant cT84.66 from tobacco leaves simultaneously expressing both light and heavy chains was analyzed by (B) ELISA and (C) by Coomassie-stained SDS/PAGE and Western blotting using the detection antibodies indicated. Protein samples correspond to leaf extract (lane 1), column flow-through (lane 2), washing step (lane 3), and elution fraction (lane 4).