Final answer:
Synthetic DNAs and fluorescent tags are used in FISH to detect specific DNA sequences within cells or tissue samples. DNA polymerase, reverse transcriptase, and DNA ligase are enzymes used in DNA replication and amplification techniques such as PCR and RT-PCR.
Step-by-step explanation:
Synthetic DNAs and fluorescent tags are used in the detection of DNA by FISH (Fluorescent In Situ Hybridization). FISH involves applying fluorescently labeled probes that are complementary to specific DNA sequences of interest within a sample. The probes hybridize, or bind, to the DNA sequences in situ, which means within the intact cells or tissue sections. The fluorescence can then be detected using a fluorescence microscope, providing information on the spatial distribution of the sequences within the cell's architecture.
In contrast, enzymes such as DNA polymerase, reverse transcriptase, and DNA ligase are used in various methods of DNA replication and amplification, like PCR (Polymerase Chain Reaction) and cDNA synthesis in RT-PCR.
During PCR, Taq polymerase, a type of DNA polymerase isolated from Thermus aquaticus, is used to replicate DNA sequences with high thermal stability, necessary for the denaturation and annealing cycles of PCR. Reverse transcriptase is used in RT-PCR to convert RNA to cDNA, and DNA ligase can be used in molecular cloning to join DNA fragments.