SKY is a powerful 24-color, whole-chromosome painting assay that allows the simultaneous visualization of each chromosome in different colors. Five spectrally distinct dyes are used in combination to create a cocktail of probes unique to each chromosome. The probe mixture is hybridized to metaphase chromosomes on a slide and then visualized with a spectral interferogram cube, which allows the measurement of the entire emission spectrum with a single exposure. The image is processed by computer software that can distinguish differences in color not discernible to the naked eye by assigning a numerical value to the spectral and pseudo color images.
SKY can detect many numerical and structural abnormalities including chromosomal material of unknown origin, complex rearrangements, translocations, deletions, duplications, aneuploidy and more. The resolution of SKY is around 1-5 Mb in size, so aberrations smaller than this may not be evident.