Figure 1. IgG antibody activity to native mouse serum albumin (MSA) in sera from animals immunized with MSA carrying various numbers of 2-hydroxyethylmethacrylate (HEMA) molecules: 3, 7, 15, or 22, respectively. Displayed are also control groups immunized with unconjugated MSA or adjuvant alone. IgG antibody activities are expressed in arbitrary ELISA units, as compared with a standard included in each of the assays. Dots denote 1 animal. Horizontal bars indicate median value. The autoantibody production was significantly higher in animals immunized with MSA carrying only 3 HEMA molecules (MSA_H3), compared with those animals that were immunized with the other conjugation degrees (n = 8 for all groups, except for the one given MSA_H22, where n = 7). The Mann-Whitney U-test was used for statistical comparison (* = p < 0.05, ** = p < 0.01, and *** = p < 0.005).