第一代基因测序流程(英语).doc

第一代测序 Sanger法DNA测序流程图 (英文)
(2011-10-16 12:22:47)
DNA sequencing enables us to perform a thorough analysis of DNA because it provides us with the most basic information of all: the sequence of nucleotides. With this knowledge, for example, we can locate regulatory and gene sequences, parisons between homologous genes across species and identify mutations. Scientists recognized that this could potentially be a very powerful tool, and so there petition to create a method that would sequence DNA. Then in 1974, two methods were independently developed by an American team and an English team to do exactly this. The Americans, lead by Maxam and Gilbert, used a “chemical cleavage protocol”, while the English, lead by Sanger, designed a procedure similar to the natural process of DNA replication. Even though both teams shared the 1980 Nobel Prize, Sanger’s method became the standard because of its practicality (Speed, 1992).
Sanger’s method, which is also referred to as dideoxy sequencing or chain termination, is based on the use of dideoxynucleotides (ddNTP’s) in addition to the normal nucleotides (NTP’s) found in DNA. Dideoxynucleotides are essentially the same as nucleotides except they contain a hydrogen group on the 3’ carbon instead of a hydroxyl group (OH). These modified nucleotides, when integrated into a sequence, prevent the addition of further nucleotides. (Speed, 1992).