Table 1.
Effects of PMA treatment on the relative DNA yield of living and dead cells from five phytoplankton species after PCR.
Fig 1.
Relationship between the percentage of the amplified DNA yield and genomic DNA yield after PMA treatment.
The line represents the identical ratio, and error bars represent the standard deviations from three independent replicates. (A) Amplified cyanobacterial and plastidial 16S rRNA and (B) amplified 18S rRNA from eukaryotic algae. The results of two cyanobacterial species, Aphanizomenon sp. and Synechocystis sp., are not represented because genomic DNA concentrations of both species were not measured during the experiments.
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.