Abstract: Multiplex (+/?) stranded analyses, such as array comparative genomic hybridization (aCGH), are provided for detecting chromosomal rearrangements associated with cancer and other diseases. For example, an illustrative multiplex array for CGH includes discrete plus (+) strand and minus (?) strand DNA probes, complementary to each other but separable on the CGH array. The minus (?) strand DNA probes recover diagnostic information lost to conventional microarrays, since many genes transcribe from the minus (?) strand. In an illustrative system, patient and control DNA samples are prepared for CGH by amplification and labeling using comprehensive primers that generate both plus (+) strands and minus (?) strands of DNA in the samples. The breakpoints of a translocated chromosome may be detected on a multiplex microarray by DNA probes of one polarity, while DNA copy number changes associated with the translocation region may be detected by corresponding DNA probes of the complementary polarity.