Figure 2.

Dose responsive curve of antibody response in immunized mice. Sera from 5 mice per group were collected 1 week after last immunization and tested by ELISA for the presence of specific antibodies by using recombinant HA or NA, or NS or M proteins. Antibody titers are expressed as the log₂ values of reciprocal endpoint titers. (a) Antibody titers of sera from mice immunized with recombinant HA, NA, M, and NS proteins produced in mammalian (COS-7) cell system; 50, 100, 150, 200 and 250 μg. (b) Antibody titers of sera from mice immunized with recombinant HA, NA, M, and NS proteins produced in prokaryotic (E. coli) cell system; 50, 100, 150, 200 and 250 μg.