The vaginal secretions cluster became much tighter when the vaginal secretion samples from donor 3 was removed; no major changes in other body fluids were observed (Fig. 4B). Overall, body
fluid types were statistically different (R2 = 0.04, p = 2 103) from each other and were characterized by very low coefficients of determination (Table 3). Not surprisingly, the highest level of similarity was observed between vaginal secretions taken postmenstruation
day 3 and day 7; results that were anticipated given that both represent the same body fluid collected at different time points (R2 = 0.8, p = 1 1015) (Table 3). It is clear that, despite the co-expression that occurs between some markers in both target and non-target body fluids, the body fluids examined in this study can easily be differentiated by means of their mRNA expression profiles (Fig. 4)