Nucleotides terminal pyrophosphate, reactions

Fig. 4. The illustration of the reverse terminator sequencing and pyrosequencing. For reverse terminator sequencing, different dNTP is labelled with different fluorescence dye. Upwn addition of each dNTP, the reaction halts and the fluorescence is the recorded. Then the terminator and fluorescence dye of dNTP is cleaved. Subsequently, the next dNTP is incorporated and the whole process is iterated. For pyrosequendng, one single dNTP flows through with the addition of the nucleotide in the corresponding position. The release of the pyrophosphate will undergo enzymatic reaction to produce light. Therefore, the camera will record which of the fragments has this dNTP at its current position.

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