Skip to main content

Table 1 Use of ROC analysis for the selection of cut-off values for individual microarray experiments.

From: Defining signal thresholds in DNA microarrays: exemplary application for invasive cancer

Array 1 Array 2
Threshold Specificity [%] Sensitivity [%] % genes below threshold* Threshold Specificity [%] Sensitivity [%] % genes below threshold*
0.010 0.0 100 0 0.005 0.0 100 0
0.030 1.8 100 0 0.010 2.5 100 0
0.040 13.4 100 0 0.015 9.3 100 0
a 0.057 49.7 99.7 0 0.020 30.5 100 0
0.060 52.7 99.6 1 a 0.027 51.0 100 0
b 0.077 68.6 99.4 7 0.030 57.7 100 1
0.080 71.1 99.4 7 b 0.031 58.6 100 1
0.100 81.3 99.0 17 0.040 75.4 99.9 12
0.120 86.8 98.2 26 0.050 89.9 99.8 20
0.140 90.0 97.7 36 0.060 93.9 99.6 29
0.170 94.9 96.5 44 0.062 94.9 99.6 31
d 0.180 95.6 96.1 44 0.064 95.6 99.9 33
c 0.192 96.6 95.8 47 c 0.066 96.0 99.5 36
0.200 97.4 95.7 48 d 0.090 98.1 98.5 43
0.300 98.6 92.8 65 0.100 99.1 98.3 45
0.400 99.5 89.9 77 0.110 100 97.6 48
0.500 100 85.0 79 0.200 100 92.0 65
0.700 100 74.7 83 0.500 100 85.7 81
1.000 100 56.6 89 0.800 100 72.4 90
1.500 100 28.7 95 1.000 100 50.8 94
2.000 100 19.4 98 1.500 100 17.1 97
3.000 100 10.2 98 2.000 100 7.7 98
5.000 100 5.4 99 2.500 100 2.9 98
10.000 100 1.2 100 3.000 100 2.1 99
12.000 100 0.0 100 5.000 100 0.0 100
  1. Specificity and sensitivity for 25 signal cut-offs from 2 microarray experiments. Three thresholds (a-c) are calculated from the negative reference controls only and compared to the threshold with maximum specificity and senitivity (TM) obtained as the point of intersection in figure 2. a: mean (TX), b: median (T0.5X), c: mean + 2 standard deviations (TX2SD); d:TM Note the different signal range for array 1 and array 2. *normalized Cy3 and Cy5 pool.