Microarray images showing technical errors detected by vRNA. (a) The two subarrays on the right show two rows each that were not printed. Additionally there are several weaker spots that indicate less PCR product spotted in those locations. (b) Image of vRNA sample channel showing a large area of low signal intensities (a portion enclosed by the white circle) where labeled sample did not hybridize well to the slide, possibly due to an air bubble. (c) Image of the biological sample from the same microarray. It is not easy to see a hybridization problem on this channel because of the large variation of signal intensities.