Analysis of glucose-6-phosphate-specific immunoglobulin production. DBA/1 mice were immunized with either 400 μg glucose-6-phosphate (G6PI), 50 μg G6PI85–99, 50 μg G6PI325–339or 50 μg G6PI469–483 in complete Freund's adjuvant. Mice were sacrificed on day 12 after immunization and titers of G6PI-specific immunoglobulins of the indicated isotypes were measured by ELISA. Data are representative of at least two different experiments (n = 4 per group; *P < 0.05 for G6PI-immunized vs. peptide-immunized mice; §P < 0.05 for G6PI325–339 vs. G6PI85–99 or G6PI469–483). OD, optical density.