Answer
DNA chips often contain segments derived from cDNA rather than genomic DNA segments because only a small portion (~1.2%) of the human genome consists of protein-coding sequences. Building a gene chip with DNA sequences corresponding to genes that are expressed increases the likelihood of "capturing" complementary segments derived from the mRNA population of the cells under study.
Work Step by Step
DNA chips often contain segments derived from cDNA rather than genomic DNA segments because only a small portion (~1.2%) of the human genome consists of protein-coding sequences. Building a gene chip with DNA sequences corresponding to genes that are expressed increases the likelihood of "capturing" complementary segments derived from the mRNA population of the cells under study.
