In DNA Microarrays, what does each spot represent?
A DNA microarray contains ordered microscopic spots, each printed with multiple identical probes complementary to a single transcriptional unit. Typically, probes correspond to a specific gene, EST, or predicted open reading frame. When fluorescently labeled cDNA or cRNA derived from samples hybridizes, intensity at each coordinate correlates with abundance of that gene's transcripts. Although a gene may contain multiple exons, array design aggregates exons under one gene identifier or multiple spots per exon in exon arrays. Spots do not represent individual primers, proteins, or isolated exon
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.
