[1] RNA probes can be produced by in vitro transcription of cloned DNA inserted in a suitable plasmid downstream of a viral promoter.
Some bacterial viruses code for their own RNA polymerases, which are highly specific for the viral promoters.
Since James Watson and Francis Crick revealed the double helix nature of DNA molecule (Watson & Crick, 1953[2]), the hydrogen bonds between the four bases are well known: adenine always binds to thymine and cytosine always binds to guanine.
It is found by two independent riboprobes, that the most important cell populations of the hippocampus, are expressing high levels of diacylglycerol lipase α (DGL-α), an enzyme involved in the production of the endocannabinoid 2-arachidonoyl-glycerol (2-AG: C23H38O4; 20:4, ω-6).
RNA probes can be used in detecting either whole embryo's development or just on tissue sections of interest.
The ability of riboprobes to bind to transcribed mRNA makes RNA probes important in research on model organisms: Drosophila, zebrafish, chick, Xenopus and mouse.
This method is useful when people want to study the translocation, deletion and duplication of chromosomes on a larger scale comparing to site-specific FISH.