*This web page was produced as an assignment for an undergraduate course at Davidson College.*
How does FISH work?
The above diagram illustrates the process of Fluorescence In-Situ Hybridization (FISH). The figure was obtained from the National Health Museum website. Permission to use this diagram is pending.
FISH Broken Down Into Five Steps:
1) Identify Probe - Researchers must prepare short sequences of DNA which are complementary to the DNA sequences that they want to examine. Click for the theory behind probes.
2) Label Probe - Once researchers have identified the probe that they are going to use, they must label the probe with fluorescent dye. Fluorescein is an example of a fluorescent marker that can be used to label the probe.
3) Denature Chromosome and Probe - First, denature the chromosomes by way of heat or pH. Then denature the probe via heat or pH.
4) Hybridization - Add the denatured chromosomes and the denatured probe to a microscope slide. Allow the probe to hybridize to its complementary site.
5) Analysis - Finally wash away the excess probe and use a fluorescence microscope to observe where the probe hybridized.
FISH Sample. Permission pending for use of this image.
*FISH is unlike many other techniques because it does not require cells to divide. FISH's ability to perform on nondividing cells makes it a highly versatile procedure. (click to see examples of FISH)
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