Figure 6

Effect of the maceration buffer, SDS and PMA Enhancer for Gram negative bacteria on the suppression of E. amylovora dead cell signals by v-dPCR. Apple branch macerates prepared either with AMB (solid columns) or 0.1xAMB (dashed columns) were inoculated with E. amylovora live (10⁶ CFU mL⁻¹), dead (10⁶ dead cells mL⁻¹) or a mixture of live (10³ CFU mL⁻¹) and dead cells (10⁶ dead cell mL⁻¹). Total cell numbers were quantified by dPCR. The effect of SDS and PMA Enhancer on viable cell quantification was assessed comparing v-dPCR viable cell counts of samples (i) only treated with PMA (100 μM); (ii) PMA plus 0.0025% (w/v) SDS (PMA + SDS); (iii) PMA plus PMA Enhancer (PMA + E). For both, total and viable cell quantification, primers targeting a 627 bp DNA sequence were used. Columns represent mean values of three independent experiments in duplicate. Error bars show the SD. Different letters denote statistically significant differences.