Spectral karyotyping, chromosomal

Spectral karyotyping involves the use of five different fluorescent probes that hybridize differentially to different sets of chromosomes. In combination with special cameras and image-pro-cessing software, this technique produces a karyotype in which every chromosome is painted a different color. This aDows the ready visualization of chromosome rearrangements such as small translocations (e.g., the Philadelphia chromosome rearrangement discussed above). 

Veldman, T., Vignon, C., Schrock, E., Rowley, J. D., and Reid, T. (1997) Hidden chromosome abnormalities in hematological malignancies detected by multi-colonr spectral karyotyping. Nat. Genet. 15, 406 10. 

Fig. 2.4 Chromosome analysis of the heterohybri-doma CB03. GTG banding (upper left), spectral karyotype analysis (upper right) and identification of human chromosomes by hybridization with specifically labeled human chromosome libraries...

Spectral karyotyping (SKY) method is a modification if the FISH technique. SKY uses a mixture of many probes specific to each cellular chromosome, each with unique color. These probes are hybridized to the metaphase chromosomes and give a general picture of all cellular chromosomes and structural chromosomal abnormalities. 

Schrock E, du Manoir S, Veldman T et al (1996) Multicolor spectral karyotyping of human chromosomes. Science 273 494-497... 

The first two methods are classification based. Classification analysis of spectral data has for some time now been used in spectral karyotyping [12] where objects (in this case chromosomes) have only one characteristic signature. Those approaches are however not suitable for the quantitative analysis of samples with possibly colocalized labels as is the case for immunostainings or GFP preparations of tissues or cells. Linear unmixing is the method best suited to analyze mixed contributions to a pixel, as is the case for colocalized labels [8,9]. 

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