Real-time PCR on faecal DNA samples. (a) Ct values of spiked samples plotted against spiked cell concentration in faecal DNA sample. (b) Ct values obtained for children (C1-C13) and adult (A1-A4) faecal samples. F0: faecal sample free of DNA. w: water instead of DNA. Values represented are means and standard deviations for 3 repetitions.