FIG 1.

Schematic overview of the two methods that were used in the validation phase of this study, in which spiked stool samples were tested for the presence of M. tuberculosis by using the GeneXpert Ultra system. (A) SOS stool processing method. (B) Slightly adapted TS stool processing method described previously by Andriyoko et al. (15). *, The SR (Cepheid) is an 8-ml mixture of sodium hydroxide (pH of >12.5) and isopropanol provided with every Xpert Ultra cartridge. #, After gravity sedimentation of the organic debris, carefully, without lifting the bottle and without disturbing the sediment, 2 ml of the upper layer of the debris-free supernatant was transferred. %, The PBS is pH 7.4.