Figure 2

Boxplots of the absolute dPCR and traditionally used methods (the correlative dPCR, the correlative qPCR and fluorescent microscopy) of heat-killed L. paracasei originally supplemented in nutritional foods (with four kinds combined). Absolute-dPCR: digital PCR without any use of standard correlative samples. Correlative-dPCR: digital PCR with standard correlative samples. Correlative-qPCR: real-time PCR with standard correlative samples. Fluorescent microscopy: PI staining to specifically penetrate into heat-killed cells with standard correlative samples. With regard to dPCR and qPCR, fundamentally tenfold dilutions of purified DNA solutions were supplied for each measurement. For the correlative qPCR, the purified DNA solution itself was also supplied, and then assay data stemming from both no- and tenfold dilutions of purified DNA solution were also combined.