A microarray consists of a flat matrix with regularly placed "spots" of DNA, each with 107 – 108 copies of the same DNA sequence. You can label fragments of human genomic DNA with a fluorescent dye and hybridized the DNA probes to the microarray. If there are sequences present in the genome that can hybridize to the spot, the spot will fluoresce, which can be detected via microscopy. Indeed, you could use such an array to detect base pair differences among different individuals, so-called SNPs (single nucleotide polymorphisms). How do you imagine such a system would work? (Hint: think about the how the conditions can affect the hybridization of DNA.)