Applicability of propidium monoazide (PMA) for discrimination between living and dead phytoplankton cells
Fig 2
Effect of PMA treatment on the genomic DNA yield and PCR quantification of defined ratios of viable and heat-killed M. aeruginosa.
The error bars represent the standard deviations from three independent replicates. (A) Mixing ratios of viable and heat-killed M. aeruginosa are as follows: living cells represent 0%, 1%, 10%, 20%, 50%, and 100% of the total cells (B) Genomic DNA yield (in percent) of the highest value according to the mixing ratio. Black bar: PMA treatment; Grey bar: non-PMA treatment. (C) PCR amplification bias according to template DNA concentration. Closed circle: Genomic DNA yield (in percent) of the highest value according to the mixing ratio in (B); Open circle: DNA yield obtained in a PCR with undiluted template DNA; Inverted closed triangle: DNA yield obtained in a PCR with diluted template DNA(1/10 dilution). (D) Correlation between normalized DNA concentrations and the corresponding Ct values after qPCR: y = −0.206x + 7.488, r2 = 0.997, P < 0.001.