Figure 1.

Schematic overview of the organization of a selective agar plate for microbiological analysis based on the drop plate method by Chen and colleagues [29]. Per plate, ten samples could be tested, each in nine dilutions, and three positive bacterial controls (PC), three negative bacterial controls (NC), and four peptone physiological salt solution sterility controls (SC) were included. Dilutions of the samples ranged from 500 to 500 × 10⁻⁸ mg caecal content per mL.