FIG. 2.

Evaluation of detection limit of the multiplex PCR. Agarose electrophoresis of the PCR products obtained from serial dilutions of S. suis S735 strain culture at a titer of 2.8 × 10⁵ CFU/ml (lane 2) and placed in tonsil biopsy specimens (1 ml of each dilution per biopsy specimen). The positions of the specific fragments of internal control, S. suis, and serotype 2 or 1/2 are indicated. Lanes: M, molecular mass marker (Smart Ladder; Eurogentec); 1, negative control of the PCR (only IPC was amplified); 3 to 8, PCR products at dilutions of 10, 10², 10³, 10⁴, 10⁵, and 10⁶.