Chromosome Painting Methods

Chromosomes are long thin molecules in the body that are composed of DNA. Chromosomes that have divided and rejoined abnormally during mitosis can form defects resulting in malformations of DNA. These malformations can cause a variety of disabilities or conditions in plants, animals and humans, Chromosome painting aides in the visualization of individual chromosomes. It also helps to view the number and structure of each individual chromosome. Highlighting individual chromosomes also helps to detect chromosomal abnormalities.

The FISH Technique

• FISH, or Fluorescent In Situ Hybridization, is a chromosome painting technique in which

  fluorescent probes are used to detect both simple and complex forms of chromosomal rearrangements. The FISH method can detect abnormalities not previously able to be detected by cytogenic banding techniques.

Array or Reverse Chromosome Painting Method

• The Array or Reverse Chromosome Painting Method is used for the rapid analysis of chromosomes. This technique is most commonly used for painting breast cancer tumor cells. With Reverse Chromosome Painting, the normal part or sections of the chromosome fluoresce.

24-Color Chromosome Painting

• Twenty-four color chromosome painting, also referred to as MFISH, is a process in which

  each chromosome is painted with a different color for easy identification of all chromosomes and abnormalities. This type of chromosome painting is fairly new and costly.

Choosing a Technique

• When choosing a chromosome painting technique, it is best to consider the application or situation for the procedure. Insurance billing guidelines need to be addressed with a representative if this process is being performed on a patient to verify which type the insurance company reimburses. The physician performing the chromosome painting also has an opinion about which method she prefers.