Karyotype
From open-encyclopedia.com - the free encyclopedia.
A karyotype is the complete set of all chromosomes of a cell. The chromosomes are arranged and displayed (often on a photo) in a standard format: in pairs, ordered by size. Karyotypes are examined in searches for chromosomal aberrations, and may be used to determine other macroscopically visible aspects of an individual's genotype, such as sex (XX vs. XY pair).
Classic karyotype
In the "classic" (depicted) karyotype, a dye, often Giemsa, is used to make bands on the chromosomes visible. This is also referred to as G-banding. Each chromosome has a characteristic banding patern which helps to identify them (notice that the two chromosomes of one pair have the same banding pattern).
Spectral karyotype (SKY technique)
In this newer technique, several different probes specific of one chromosome pair, carrying different amounts of a set of fluorescents dyes, are hybridized to the chromosomes (Fluorescent In Situ Hybridation (FISH)). This give each chromosome pair unique spectral characteristics due to the relative amount of each of the fluorochromes. Chromosomes can be automatically identified in fluorescence microscopy through an interferometer and a computer analysis (spectral imaging)
See also
de:Karyogramm es:cariotipo fr : caryotype
