Fig. 1.

Coefficients of absorbance between CP sera pool and WP sera pool after checkerboard ELISA analysis of Kgp synthetic peptides. Brazil, 2018. CP: chronic periodontitis; WP: without periodontitis. The coefficient is the difference of the O.D. value between the sera pools, and it expresses the difference of the mean IgG levels between the CP and the WP sera pools. P. gingivalis (Pg) extract and peptides were used as the antigen in the indirect ELISA test. 1:100 and 1:250 serum concentrations are represented. Kgp12 presented a higher coefficient between CP and WP sera pools in 1:250 serum concentration. Checkerboard ELISA best acquired condition: 5 µg/mL Pg extract concentration, 10 µg/mL peptide concentration, 1:250 sera pool concentration and 1:25,000 anti-human IgG peroxidase conjugate concentration. The nature of the data does not allow statistical analysis between the coefficients