Centromere probes target the centromeric region of the particular chromosome. These probes allow us to enumerate the number of centromeres and thus chromosomes of a particular kind. Centromere probes bind to repetitive alpha satellite DNA sequences. Repetitive sequence DNA is tightly coiled throughout the cell cycle unlike other DNA.
Centromere probes can be used individually to detect monosomy or aneuploidy of a chromosome.
For example, centromere 3 is an important probe to use in the evaluation of uveal melanoma cases. The presence of monosomy 3 is indicative of more aggressive disease and metastatic potential.
Centromere probes are often used as a reference probe for many genes. For example, centromere 17 is used as a reference probe for HER2/neu.
In the image, each rectangular symbol (indicated by the arrows) represents the specific DNA sequence that spans the centromere. The green elliptical symbol is the fluorescent tag or dye.
