DIDEOXY SEQUENCING Meaning and
Definition
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Dideoxy sequencing, also known as Sanger sequencing, is a laboratory technique used to determine the exact order or sequence of nucleotides within a DNA molecule. This method was developed by Frederick Sanger in the late 1970s and is widely used in molecular biology and genetic research.
In dideoxy sequencing, a DNA sample is first denatured or heated to separate its two strands. Small fragments of DNA containing the target sequence are then mixed with a DNA polymerase enzyme, a primer, and a mixture of normal deoxynucleotides (dNTPs) and chain-terminating dideoxynucleotides (ddNTPs). The dideoxynucleotides lack a hydroxyl group, preventing further nucleotide addition once incorporated into the growing DNA chain.
When the DNA polymerase encounters a ddNTP, it incorporates it into the growing DNA chain instead of a dNTP. Since ddNTPs are labeled with different fluorescent dyes or radioisotopes, the chain-termination event is detected during subsequent analysis.
After the sequencing reaction, the fragments are separated by size using gel electrophoresis, creating a series of DNA fragments that differ by one nucleotide. The fragments are then detected and analyzed, with the order of nucleotides deduced based on their migration pattern.
By generating a ladder-like pattern of labeled fragments, dideoxy sequencing allows the determination of the DNA sequence. This information has profound applications in many fields, including genetic diagnostics, genetic engineering, and understanding the genetic basis of diseases.
Common Misspellings for DIDEOXY SEQUENCING
- sideoxy sequencing
- xideoxy sequencing
- cideoxy sequencing
- fideoxy sequencing
- rideoxy sequencing
- eideoxy sequencing
- dudeoxy sequencing
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- dkdeoxy sequencing
- dodeoxy sequencing
- d9deoxy sequencing
- d8deoxy sequencing
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- dixeoxy sequencing
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- difeoxy sequencing
- direoxy sequencing
- dieeoxy sequencing
- didwoxy sequencing
- didsoxy sequencing
Etymology of DIDEOXY SEQUENCING
The word "dideoxy sequencing" originates from the combination of two main components: "dideoxy" and "sequencing".
1. Dideoxy: The term "dideoxy" refers to a type of nucleotide used in this particular sequencing method. Dideoxynucleotides are chemically altered versions of the four standard nucleotides (A, T, G, and C) used in DNA sequencing. These modified nucleotides lack the 3'-OH group, which is required for the formation of a phosphodiester linkage necessary for DNA polymerization. Incorporation of a dideoxynucleotide prevents further DNA chain elongation, allowing the determination of the DNA sequence during sequencing reactions.
2. Sequencing: The term "sequencing" refers to the process of determining the precise order of nucleotides in a DNA molecule.
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