Figure 2

Specificity and sensitivity of select cut-offs for individual microarrays. Specific (spiked B. subtilis and housekeepers) and non-specific hybridization control groups (plant, bacterial and viral genes) represent sensitivity (squares) and specificity (circles), respectively. The intersection point of the two graphs indicates the threshold T_M at which Sp equals Se. T_M values were 0.18 (array1) and 0.09 (array 2). Indicated thresholds a-d are described in table 1. The Tj values presented in Table 1 were used to construct these curves. Note the different signal range (abcissa values) for array 1 (A) and array 2 (B).