7/26/2023 0 Comments Touchdown pcrGenerally the higher the annealing temperature, the better the matching of the primers and templates. The first cycle (initial) annealing temperature is set 3~5☌ higher than the expected temperature. In MT-PCR this is decreased with each cycle. The big difference between MT-PCR and multiple PCR is the annealing temperature. Only target DNAs with different length of DNA pairs are selected for multiple PCR.Īlthough multiple PCR saves time, it still cannot prevent errors caused by the cross amplification of non-target DNA. Therefore we have to select the specific target DNAs in advance before we do the multiple PCR. However, the use of multiple PCR has a serious disadvantage, it is not easy to avoid cross-amplification of non-target DNA in a mixture of primers and DNAs. Much time can be saved by using multiple primers and target DNAs in one reaction where we can extend several target DNAs in a single PCR at the same time*(2). In a regular PCR experiment, the target is a single DNA template and a specific primer will extend the template in 20 reaction cycles. How does MT-PCR solve the issue of multiple PCR? MT-PCR successfully identifies several different target bacterial DNAs, it also prevents the reaction from amplifying non-target DNA and consequent false positive results. MT-PCR, which was presented in a new study in 2016*(1), was developed for the detection of resistance genes. The annealing temperature is reduced from an original set point by 0.5~1☌ for each cycle until the best annealing temperature is reached. Severa l primers are used to test multiple DNA targets in one PCR experiment. MT-PCR combines features of both multiple PCR and touchdown PCR. Fortunately, PCR techniques have constantly improved over the years and a new PCR technique - Multiple Touchdown PCR (MT-PCR) has been developed. However, the most overwhelming problem that arises in PCR is the amplification of non-target DNA which can cause all kinds of trouble, not the least being false positive results. Polymerase chain reaction, or PCR, has been in use for nearly 30 years and is in use in all kinds of biochemical and medical laboratories. Multiple Touchdown PCR (MT-PCR): A New Application of PCR for Better Precision and Stability What is MT-PCR?
0 Comments
Leave a Reply. |