Fig. 2. Comparison of DESI-MS classification performance between different vaginal microbiome compositions.

A ROC-curve analysis showing performance of direct swab analysis by DESI-MS operating in both negative and positive ion polarity modes to predict Lactobacillus-depleted vaginal microbiome compositions in both the VMET (blue; AUC: 94.1, sensitivity: 62.0, specificity: 97.8) and VMET2 (red; AUC: 90.6, sensitivity: 54.5, specificity: 96.4) patient cohorts. Discrimination between the major vaginal community state types (CST) could also be readily achieved using DESI-MS across both patient cohorts, including B CST I vs IV, C CST III vs IV and D CST I vs III. Overall, predictive performance of DESI-MS was comparable to that of models constructed from LC-MS assays (Supplementary Table 3 and Supplementary Fig. 4).