Reverse Northern blot
Encyclopedia
The reverse northern blot is a variant of a northern blot
in which the nucleic acid immobilized on a membrane is a collection of isolated DNA
fragments rather than RNA
, and the probe
is RNA extracted from a tissue and radioactively labelled.
DNA microarrays use methods akin to the reverse procedure, in that they involve the use of isolated immobilized DNA fragments, and hybridization with a probe made from cellular RNA. Thus the reverse northern blot, 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.
Northern blot
The northern blot is a technique used in molecular biology research to study gene expression by detection of RNA in a sample. With northern blotting it is possible to observe cellular control over structure and function by determining the particular gene expression levels during differentiation,...
in which the nucleic acid immobilized on a membrane is a collection of isolated DNA
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
fragments rather than RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
, and the probe
Molecular probe
A molecular probe is a group of atoms or molecules attached to other molecules or cellular structures and used in studying the properties of these molecules and structures. Radioactive DNA or RNA sequences are used in molecular genetics to detect the presence of a complementary sequence by...
is RNA extracted from a tissue and radioactively labelled.
DNA microarrays use methods akin to the reverse procedure, in that they involve the use of isolated immobilized DNA fragments, and hybridization with a probe made from cellular RNA. Thus the reverse northern blot, 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.