dideoksinukleotidit

Dideoxynucleotides are synthetic analogs of natural deoxyribonucleotides, which are the building blocks of DNA. They are used in molecular biology and biochemistry for various applications, particularly in the synthesis of DNA and RNA. The term "dideoxynucleotide" refers to nucleotides that lack a 3'-hydroxyl group, which is essential for DNA chain elongation during replication. This modification prevents further elongation of the DNA strand, making dideoxynucleotides useful as chain terminators in DNA sequencing techniques.

Dideoxynucleotides are typically used in the Sanger sequencing method, where they are incorporated into DNA strands during replication. The absence of the 3'-hydroxyl group causes the DNA polymerase to terminate chain elongation, resulting in a mixture of DNA fragments of varying lengths. These fragments can be separated by size using techniques such as gel electrophoresis, allowing for the determination of the sequence of the original DNA template.

In addition to their use in sequencing, dideoxynucleotides have applications in other areas of molecular biology. For example, they can be used in primer extension reactions to synthesize specific DNA fragments or in the synthesis of DNA probes for hybridization experiments. Dideoxynucleotides are also used in the synthesis of DNA aptamers, which are short, single-stranded DNA or RNA molecules that bind specifically to a target molecule.

The synthesis of dideoxynucleotides involves the chemical modification of natural deoxyribonucleotides, typically by replacing the 3'-hydroxyl group with a hydrogen atom. This modification can be achieved using various chemical reagents and methods, depending on the specific nucleotide and the desired application. Dideoxynucleotides are commercially available from several suppliers and are widely used in molecular biology laboratories worldwide.