The apoE cDNA was amplified from four months old fetus liver tissue mRNA by RT PCR. It was inserted into the TOPO ○R vector, whose sequence is the same as that reported. The right apoE cDNA was inserted into pQE30 vector to construct pQE30 apoE recombinant expressed plasmid, which was expressed as a histidine tag fusion protein in E.coli strain BL21(DE3) with higher level. The purified protein was gained by Ni NTA column. SDS PAGE showed that 34 kD protein was expressed. Western blot analysis showed a positive band at 34 kD.
