FISH conceptual drawing

So you have this gene whose nucleotide sequence is known to you but its chromosomal location (locus) is unknown, how do you go about finding this locus? The short answer is FISH i.e fluorescence in situ hybridization.

Here’s a quick list of the steps of FISH technique:

1- prepare a fluorescent probe (short nucleotide sequence complementary to the gene of interest)

2- denature the metaphasic chromosomes

3-incubate the probe with the partially denatured chromosomes and wait for it to hybridize with the gene of interest

4-visualize the locus of the gene by visualizing the probe i.e. use a fluorescence microscope to see where the probe is and thus visualize the location of the gene on the chromosome.

the figure below, taken from a wikipedia article you can find here shows the simplified concept of this technique.


Hope this helps


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