A. SDS-PAGE analysis (4–20 % acrylamide gradient) under reducing conditions of recombinant rat apoE (5 μg) obtained using a plasmid bearing optimized (Left) or non-optimized (Right) codons. The molecular mass standards are shown in the first lane. B. Western blot analysis of recombinant rat apoE (0.2 μg) using anti-apoE antibody mAb1D7 (Left) and mAb3H1 (Right); lanes 1 and 5, rat apoE; lanes 2 and 6, human apoE3; lanes 3 and 7, human apoE3(1-191); lanes 4 and 8, human apoE(201-299). C. Analytical RP-HPLC analysis of recombinant rat apoE (100 μg protein) obtained using a plasmid bearing optimized (Left) or non-optimized (Right) codons. Following the Ni-affinity chromatography step, the samples were loaded on a Zorbax C-8 HPLC column and eluted at 0.25 ml/min with a linear AB gradient of 2% B/min, where A is 0.05% aqueous TFA and B is acetonitrile containing 0.05% TFA.