<Ul> <Li> An array or slide is a collection of features spatially arranged in a two dimensional grid, arranged in columns and rows . </Li> <Li> Block or subarray: a group of spots, typically made in one print round; several subarrays / blocks form an array . </Li> <Li> Case / control: an experimental design paradigm especially suited to the two - colour array system, in which a condition chosen as control (such as healthy tissue or state) is compared to an altered condition (such as a diseased tissue or state). </Li> <Li> Channel: the fluorescence output recorded in the scanner for an individual fluorophore and can even be ultraviolet . </Li> <Li> Dye flip or dye swap or fluor reversal: reciprocal labelling of DNA targets with the two dyes to account for dye bias in experiments . </Li> <Li> Scanner: an instrument used to detect and quantify the intensity of fluorescence of spots on a microarray slide, by selectively exciting fluorophores with a laser and measuring the fluorescence with a filter (optics) photomultiplier system . </Li> <Li> Spot or feature: a small area on an array slide that contains picomoles of specific DNA samples . </Li> <Li> For other relevant terms see: <Ul> <Li> Glossary of gene expression terms </Li> <Li> Protocol (natural sciences) </Li> </Ul> </Li> </Ul> <Li> An array or slide is a collection of features spatially arranged in a two dimensional grid, arranged in columns and rows . </Li> <Li> Block or subarray: a group of spots, typically made in one print round; several subarrays / blocks form an array . </Li> <Li> Case / control: an experimental design paradigm especially suited to the two - colour array system, in which a condition chosen as control (such as healthy tissue or state) is compared to an altered condition (such as a diseased tissue or state). </Li>

What does detection of a fluorescent signal from one of the spots of a dna microarray indicate