Reverse Northern Blot
A variant of the procedure known as the reverse northern blot is occasionally used. In this procedure, the substrate nucleic acid (that is affixed to the membrane) is a collection of isolated DNA fragments, and the probe is RNA extracted from a tissue and radioactively labelled.
The use of DNA microarrays that have come into widespread use in the late 1990s and early 2000s is more akin to the reverse procedure, in that they involve the use of isolated DNA fragments affixed to a substrate, and hybridization with a probe made from cellular RNA. Thus the reverse procedure, though originally uncommon, enabled northern analysis to evolve into gene expression profiling, in which many (possibly all) of the genes in an organism may have their expression monitored.
Read more about this topic: Northern Blot
Famous quotes containing the words reverse, northern and/or blot:
“During the late war [the American Revolution] I had an infallible rule for deciding what [Great Britain] would do on every occasion. It was, to consider what they ought to do, and to take the reverse of that as what they would assuredly do, and I can say with truth that I was never deceived.”
—Thomas Jefferson (1743–1826)
“I have found that anything that comes out of the South is going to be called grotesque by the Northern reader, unless it is grotesque, in which case it is going to be called realistic.”
—Flannery O’Connor (1925–1964)
“Lo, thus, as prostrate, ‘In the dust I write
My heart’s deep languor and my soul’s sad tears.’
Yet why evoke the spectres of black night
To blot the sunshine of exultant years?”
—James Thomson (1834–1882)