FISH is used for which of the following?

Ans. D. All the aboveFluorescent in situ Hybridization (FISH):-Any cloned locus can be mapped to its position on a metaphase chromosome by fluorescent in situ hybridization (FISH). A sample of cells arrested in the process of division is placed on a microscope slide, and the chromosomes are fixed and the DNA is carefully denatured while still retaining its fundamental chromosome organization. A labeled probe prepared from a cloned DNA fragment is then placed on the slide and incubated to allow hybridization to occur on the chromosome in situ. After removing un-hybridized probe, the chromosome can be viewed under UV light with a microscope so that fluorescent regions and chromosome banding landmarks can be correlated. The resolution of this technique, however, is only as good as the resolution of karyotype bands. Standard DNA cloned fragments of about 100 kb each for use as FISH probes are available from many genetic resource centers worldwide as bacterial artificial chromosomes (BACs).Examples of FISH applicationsDiagnosticResearchThe identification of specific chromosome abnormalitiesThe identification of new non-random abnormalities (by M-FISH or SKY)The characterization of marker chromosomesGene mappingInterphase FISH for specific abnormalities in cases of failed cytogeneticsIdentification of regions of amplification or deletion by CGHMonitoring disease progressionThe identification of translocation breakpointsMonitoring the success of bone marrow transplantationThe study of 3D chromosome organization in interphase nuclei