Specificity of the RCA assay. RCA results monitored by the RotorGene 6000 real-time PCR machine (Corbett research). The accumulation of double-stranded DNA was detected by staining with Sybr Green I. RCA signals indicating the presence of the mutation of interest ((labeled as "positive signal") are shown as exponential increases in fluorescence. The experiment was conducted using the Ca-Y132H-specific RCA probe and tested on eight C. albicans isolates with known ERG11 mutation sites (Table 1). Ligation-mediated RCA with matched templates (DNA from isolates C527, C594, C507) containing the targeted SNPs produced "positive signals". Other templates showed an absence of signal (labeled as "negative signal").