Figure 4. Multiplex detection of four plant pathogens.

Acidovorax avenae subsp. citrulli (Aac) (10⁸ CFU mL^{− 1}), chilli vein-banding mottle virus (CVbMV) (0.2 µg mL^{− 1}), watermelon silver mottle virus (WSMoV) (5 µg mL^{− 1}), melon yellow spot virus (MYSV) (10 µg mL^{− 1}) and mixed pathogens (10⁸ CFU mL^{− 1}) Aac, 0.2 µg mL^{− 1} CVbMV, 5 µg mL^{− 1} WSMoV and 10 µg mL^{− 1} MYSV) in (A) 1% casein in PBST and (B) artificially spiked healthy watermelon leaf extract were tested using immuno microsphere. Antibody (MPC, 1B4, 2D6 and 5E7) coated microspheres were used to detect Aac, CVbMV, WSMoV and MYSV, respectively. Normalized signal (Y-axis) is a ratio of signal obtained from pathogen detection in the samples to the signal obtained when no pathogen was present. Each dataset was plotted as a mean of duplicates ± standard deviation.