Editing Karyotype (section)

===Multicolor FISH (mFISH) and spectral karyotype (SKY technique)===

[[File:Sky spectral karyotype.png|thumb|Spectral karyogram of a human female]]

Multicolor [[Fluorescence in situ hybridization|FISH]] and the older spectral karyotyping are molecular [[cytogenetic]] techniques used to simultaneously visualize all the pairs of [[chromosome]]s in an organism in different colors. [[Fluorescent]]ly labeled probes for each chromosome are made by labeling chromosome-specific DNA with different [[fluorophore]]s. Because there are a limited number of spectrally distinct fluorophores, a combinatorial labeling method is used to generate many different colors. Fluorophore combinations are captured and analyzed by a fluorescence microscope using up to 7 narrow-banded fluorescence filters or, in the case of spectral karyotyping, by using an [[interferometer]] attached to a fluorescence microscope. In the case of an mFISH image, every combination of fluorochromes from the resulting original images is replaced by a [[false color|pseudo color]] in a dedicated image analysis software. Thus, chromosomes or chromosome sections can be visualized and identified, allowing for the analysis of chromosomal rearrangements.<ref>{{cite journal  |vauthors=Liehr T, Starke H, Weise A, Lehrer H, Claussen U |title=Multicolour FISH probe sets and their applications |journal=Histol. Histopathol. |volume=19 |issue=1 |pages=229–237 |date=January 2004 |pmid=14702191 }}</ref>
In the case of spectral karyotyping, image processing software assigns a [[false color|pseudo color]] to each spectrally different combination, allowing the visualization of the individually colored chromosomes.<ref>{{cite journal  |vauthors=Schröck E, du Manoir S, Veldman T, etal |title=Multicolor spectral karyotyping of human chromosomes |journal=Science |volume=273 |issue=5274 |pages=494–7 |date=July 1996 |pmid=8662537 |bibcode=1996Sci...273..494S |doi=10.1126/science.273.5274.494|s2cid=22654725 }}</ref>

[[File:Spectralkaryotype98-300.jpg|thumb|left|Spectral human karyotype]]

Multicolor FISH is used to identify structural chromosome aberrations in cancer cells and other disease conditions when Giemsa banding or other techniques are not accurate enough.