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PNA-mediated Whiplash PCR. J. A. Rose et al. DNA7 poster Summarized by Shin, Soo-Yong 2001. 8. 8. Abstract. Whiplash PCR (WPCR) Recursive, self-directed polymerase extension of a mixture of DNA hairpins. Problems : backhybridization
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PNA-mediated Whiplash PCR J. A. Rose et al. DNA7 poster Summarized by Shin, Soo-Yong 2001. 8. 8
Abstract • Whiplash PCR (WPCR) • Recursive, self-directed polymerase extension of a mixture of DNA hairpins. • Problems : backhybridization • In this paper, WPCR is modeled by a statistical thermodynamic model & Markov chain. • To prevent backhybridization, PNA2/DNA triplex formation (P-WPCR) will be proposed. (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
WPCR • Computational steps are implemented by the template-directed, recursive polymerase extension of a mixture of DNA hairpins. (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
WPCR • In the original protocol, computation begins with a reduction in reaction temperature. • A computational transition occurs by the polymerase extension of hybridization head. • Stop sequence is implemented by a length 3 poly0A sequence (absence of free dTTP) • After polymerization, hairpins are thermally denatured. (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
Drawbacks of WPCR • A tendency for extended molecules to participate in backhybridication More stable Less stable (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
Statistical model • Assume encounters/strand • More study is needed. (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
PNA mediated WPCR • WPCR architecture may be redesigned to enable the specific inhibition of backhybridized structures by targeted PNA2/DNA triple formation. • Polyamine nucleic acid (PNA) bind to complementary ssDNA with extremely high affinity • Under appropriate reaction condition, rapid, irreversible formation of the triplex structure occurs even if the target DNA single strand is involved in hybridization. (strand invasion) • Triplex formation : P-loop (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
PNA mediated WPCR • The sequence TTTTCTTCTT • ssDNA target sequence of the highly efficient cationic bis-PNA molecules. (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/
PNA mediated WPCR (C) 2001, SNU Biointelligence Lab, http://bi.snu.ac.kr/