Painting Probes

Painting probes (sometimes referred to as Coatasomes or WCP's) are actually many separate region-specific probes that bind along a single chromosome, together giving the illusion of "painting" the whole chromosome.

Here is an example of a 19 painting probe. The normal 19's are the two right-hand bright yellow chromosomes. The leftmost bright signal is a portion of chromosome 19 attached to another chromosome. This test was used to confirm the identity of the extra material as chromosome 19 material.

Here is a case where a person had an unbalanced translocation where a portion of the end of the long arm of chromosome 4 replaced the end of the long arm of chromosome 1:

The abnormal chrom.1 resulting from the translocation is on the right in the left-hand pair; the right-hand pair shows normal chromsome 4's

FISH was performed using painting probes:

This shows a probe which highlights the whole chromosome 1.
Notice the red tip on the upper chromosome which represents
the piece of chrom 4 attached to the end

Here, the probe is for chromosome 4, which shows the translocation onto chromsome 1
(the large sphere at the top is a nucleus from another cell in interphase)

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