Dictionary > Reverse banding

Reverse banding

Definition
noun
(cytogenetics) A chromosome banding method that employs Giemsa staining technique that produces bands complementary to G-bands
Supplement
Cytogeneticists use banding techniques to determine the characteristic pattern of light and dark bands on a chromosome under a microscope. They make use of diagrams referred to as chromosome ideograms to determine the relative sizes and the banding patterns of chromosomes. By applying specific stains, the banding patterns become apparent. The different types of banding are Giemsa (G-) banding, reverse (R-) banding, constitutive heterochromatin (C-) banding, quinacrine (Q-) banding, Nucleolar Organizer Region (NOR-) banding, and telomeric R (T-) banding.
Reverse banding is a banding technique first described by Dutrillaux and Lejeune. They observed that if chromosomes were treated with 0.02 M phosphate buffer (pH 6.5) at 87° for ten minutes, then stained with Giemsa, the banding pattern was the opposite of G-banding.1 In G-banding, the banding pattern is a series of light and dark bands on a chromosome. Regions in the chromosome that stain lightly tend to be euchromatic, rich with guanine and cytosine and more transcriptionally active whereas regions that stain darkly tend to be heterochromatic, rich with adenine and thymine and less transcriptionally active. In reverse banding, the dark regions of the chromosomes tend to be euchromatic and rich in guanine and cytosine whereas the light regions tend to be heterochromatic and rich in adenine and thymine. The banding pattern produced is the reverse of G-banding (thus, the name).
Together with G-banding, reverse banding technique is used on human karyotype in order to determine chromosomal deletions.
Also called:

  • R-banding
  • R banding

See also:

Reference(s):

1 Stein, G., Stein, J. & Kleinsmith, L. (1978). Methods in cell biology. London: Academic Press. p.60.


You will also like...

Freshwater aquatic plankton
Freshwater Communities & Plankton

Planktons are microscopic organisms that live suspended in aquatic habitats. There are two groups: the phytoplanktons an..

Chromosomes X and Y and Sex Determination
Chromosomes X and Y and Sex Determination

This tutorial looks at sex determination via the sex chromosomes, X and Y. Read it to get more info on X and Y chromosom..

primitive arthropods
Arthropods

The arthropods were assumed to be the first taxon of species to possess jointed limbs and exoskeleton, exhibit more adva..

Origins of Life on Earth
Origins of Life on Earth

Earth was created around 4.5 billion years ago and life began not long after. Primitive life likely possessed the elemen..

Developmental Biology
Developmental Biology

Developmental biology is a biological science that is primarily concerned with how a living thing grows and attains matu..

takahē
Takahē (Porphyrio hochstetteri)

Meet the colorful takahē, an extremely rare flightless bird. Find out more about its unique features and why they matte..

Related Articles...

No related articles found

See all Related Topics