Sensitive and highly specific detection of Cronobacter sakazakii based on monoclonal sandwich ELISA

Abstract

A sensitive and specific monoclonal antibody-based sandwich enzyme-linked immunosorbent assay (ELISA) was established to detect the Cronobacter sakazakii. A pair of monoclonal antibodies (mAbs) selected from mAbs produced by 11 murine hybridomas was selected for the sandwich ELISA procedure. Targets of two mAbs were 100 kDa and 42 kDa protein extracted from the bacteria, respectively, which were proved by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting analysis. The limit of detection of this method was established as 1 × 104 cfu/mL, and the linear range from 1 × 105 to 1 × 108 cfu/mL. In the real sample test, 1 cfu/g C. sakazakii was detected in artificially contaminated powdered infant formula with 4 h enrichment.