What is dideoxynucleotide?

Dideoxynucleotides are nucleotides that lack the 3'-hydroxyl group necessary for the formation of phosphodiester bonds during DNA synthesis. They are commonly used in DNA sequencing techniques, specifically Sanger sequencing, where they are incorporated into the growing DNA strand to terminate further elongation. This results in a series of DNA fragments of varying lengths that can be separated and analyzed to determine the sequence of the original DNA template.

Dideoxynucleotides are labeled with fluorescent dyes or radioisotopes to facilitate detection and analysis of the DNA fragments. They are similar in structure to deoxynucleotides, with the exception of the missing 3'-hydroxyl group.

Overall, dideoxynucleotides play a crucial role in DNA sequencing methods and have greatly contributed to the advancement of genetic research and technology.