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Fred Sanger was a British biochemist who made significant contributions to the field of genetics and biochemistry. He is one of the few scientists to have been awarded the Nobel Prize in Chemistry twice.
Sanger's first Nobel Prize was awarded in 1958 for his work on the structure of proteins, particularly insulin.
However, his second Nobel Prize in 1980 was for his development of the DNA sequencing technique, which revolutionized the field of genomics.
His approach to DNA sequencing is often referred to as the Sanger method.

The Dideoxy Chain Termination method, also known as the Sanger sequencing method, is a technique used to determine the nucleotide sequence of DNA.
This method involves synthesizing new DNA strands based on a single-stranded template. The process uses a primer that binds to the DNA template and a DNA polymerase enzyme to synthesize the complementary strand.
A crucial aspect of this method is the incorporation of dideoxynucleotides, which cause the termination of DNA synthesis when they are added to the growing DNA strand.
Due to the lack of a 3'-OH group, dideoxynucleotides prevent any further nucleotides from being added, effectively halting DNA synthesis at specific points.
The resulting DNA fragments of varying lengths are then analyzed to determine the sequence of the original DNA template.

Dideoxynucleotides (often abbreviated as ddNTPs) are modified nucleotides used in the Sanger sequencing method.
Unlike regular deoxynucleotides (dNTPs), dideoxynucleotides lack the 3'-hydroxyl (3'-OH) group on the sugar molecule.
This missing 3'-OH group prevents the formation of a phosphodiester bond with the next nucleotide, thus terminating DNA chain elongation.
In Sanger sequencing, four types of dideoxynucleotides are used, each labeled with a different fluorescent dye corresponding to one of the four DNA bases: adenine (A), cytosine (C), guanine (G), and thymine (T).
When incorporated into the growing DNA strand, the fluorescent dyes provide a way to identify the end nucleotide of each fragment, allowing the sequence to be read after separation by electrophoresis.
This method of using ddNTPs to terminate DNA synthesis was a pivotal innovation in the development of more advanced DNA sequencing techniques.