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

BMC Genomics

Table 2 ROC parameters for different negative control groups.

	Threshold with maximum specificity and sensitivity^*	β error	α error	Threshold value for α = 0.05	Discriminatory power (Area under ROC plot)
Array 1	0.40 (+SSC)	0.101	0.096	0.50	0.969
	0.18 (-SSC)	0.039	0.044	0.17	0.994
Array 2	0.25 (+SSC)	0.089	0.099	0.33	0.984
	0.09 (-SSC)	0.015	0.019	0.06	0.999

SCC spots or spots with deposited DNA perform differently in ROC-analysis yielding different areas under the ROC curve as well as different thresholds with maximum specificity and sensitivity. The area under the ROC curve may be used as an indicator for microarray hybridization quality. ^*characterized by smallest α and β errors. Note that in this case the α error can be >0.05.

ISSN: 1471-2164