DNA sequence

In molecular biology research, DNA sequence analysis is further research and the basis of the target gene. At present the technology for sequencing, and other major Sanger (1977) invented the end-mediated chain termination method and Maxam and Gilbert (1977) invented the chemical degradation method. This two kinds of methods in principle, very different, but are based on the nucleotide in a fixed point, random in a particular base at the end, a A, T, C, G four different length of the A series of nucleotides, and then urea degeneration PAGE gel electrophoresis test to obtain DNA sequence. Currently Sanger sequencing method has been widely used. Sanger sequencing method is the principle of using a combination of DNA polymerase to extend the template sequence to be determined on the primer. Until the introduction of a chain of nucleotides termination. Each time a sequence of four separate from the reaction composition, each containing all four reaction deoxynucleotidyl triphosphate (dNTP), and mixed with a limited number of different dideoxy nucleoside triphosphate (ddNTP) . As ddNTP lack of extension of the required 3 - OH group, to extend the oligonucleotide selective in G, A, T, C or terminated. Termination points from the corresponding reaction dideoxy on. Each of dNTPs ddNTPs and the relative concentration can be adjusted so that the reaction of several hundred to several thousand head of a base linked to terminate the product. They have a common starting point, but terminated in different nucleotide, through high-resolution degeneration gel electrophoresis separation of fragments of different sizes, the gel can be used after X-ray film Autoradiography or non-isotopic tags Jin