Fig. 2
From: Detecting eukaryotic microbiota with single-cell sensitivity in human tissue
Detection of positive controls with single-index primers and dual-index primers. Detection of a P. falciparum, b T. gondii, and c Saccharomyces (cerevisiae) in healthy placental samples and positive controls with single-index primers. The same samples were re-analyzed with dual-index primers for detection of d P. falciparum, e T. gondii, and f Saccharomyces (cerevisiae). Graphs illustrate kit blanks (left; n = 5), healthy placental samples (middle; n = 44 placental biopsies from four women), and positive controls (right [0 to 10,000 added genome copies ordered from left to right]; n = 6). With a dual-index sequencing approach, the P. falciparum and T. gondii signals disappear from all the healthy placental samples (n = 44) and the 0 genome copy control. Signal remains in the positive control samples (right side of graphs; n = 5). The high proportion of S. cerevisiae reads in blanks (f) was due to an overall low number of total reads in the blanks using dual-index primers. The absolute number of Saccharomyces 18S reads with the dual-index primers is presented in Additional file 1: Figure S3