Complement is part of the host’s natural defense mechanisms against pathogens. Its exploration is based in first intention on a quantitative evaluation of the C3 and C4 fractions by automated and standardized immunoassay techniques. Serum protein electrophoresis (SPEP) separates proteins into 6 fractions. The beta-2 globulin fraction contains complement C3-C4, the amplitude of which allows their quantification. In this context, we carried out a comparative study between the two assay techniques. We included all patients who had simultaneously received a weight determination of the C3 and C4 fractions by turbidimetry on a SPA Plus® automaton and an SPEP on a Capillarys Sebia® automaton over a period of one year. Our study demonstrated a positive correlation between these two methods with Pearson r=0.801, P-value<0.001. Studies have reported that SPEP can be used for the detection of hypocomplementemia by a decrease in the fraction of beta-2 globulins. In capillary electrophoresis (Capillarys Sebia®), beta-2 globulins contain almost exclusively complement. To date, our study is the first to seek the correlation between two electrophoretic and turbidimetric methods for the quantification of complement.