Talk:Touchdown polymerase chain reaction

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Is the origin of the name Touchdown PCR known? Ian Glenn 03:29, 4 April 2007 (UTC)[reply]

Presumably it comes from the "touchdown" effect caused by the slowly decreasing annealing temperature. The primers bind the DNA more slowly and controlled than at a high annealing temperature in a gentle touchdown... I guess it would say in Don R, Cox P, Wainwright B, Baker K, Mattick J (1991). "'Touchdown' PCR to circumvent spurious priming during gene amplification". Nucleic Acids Res. 19 (14): 4008.

PMID 1861999.{{cite journal}}: CS1 maint: multiple names: authors list (link) but I cant access the full article. - Zephyris _Talk 11:51, 4 April 2007 (UTC)[reply

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Well got hold of the paper, to quote: "The annealing temperature of the reaction is decreased 1 °C (in this example) every second cycle from 65°C to a 'touchdown' at 55 °C, at which temperature 10 cycles are carried out." Not much of an answer really... - Zephyris _Talk 11:56, 4 April 2007 (UTC)[reply]

The reduction in temperature does not necessarily have to be every 2 cycles, nor does it necessarily need to be by 1 degree celsius. I routienly use a touchdown PCR that drops the annealing temperature by 1 degree every cycle for 10 cycles. Perhaps the article should be less specific about actual parameters. As quoted from the paper "The annealing temperature of the reaction is decreased 1 °C (in this example) every second cycle from 65°C to a 'touchdown' at 55 OC, at which temperature 10 cycles are carried out." Note the bit about "(in this example)."

Okay, thanks. I'll edit the article accordingly.--Seans Potato Business 15:35, 25 April 2007 (UTC)[reply]

Does the sentence "The primer will anneal at the highest temperature which is least-permissive of nonspecific that it is able to tolerate." make sense to you? I don't understand it; is it missing punctuation or something? --Seans Potato Business 15:35, 25 April 2007 (UTC)[reply]

I suggest "The primer will anneal at the highest tolerable temperature which is least-permissive of nonspecific binding to the template." Evolume 01:39, 27 April 2007 (UTC)[reply]