PAP (Pyrophosphorolysis-activated polymerization)/ KlenTaq-S
PAP is a unique method for DNA amplification (Liu and Sommer: BioTechniques, 29 , 1072-1080; Nucleic Acids Res, 30 , 598-604), where pyrophosphorolysis and polymerization are serially coupled by DNA polymerase using 3’ blocked primer. Pyrophosphorolysis is the reverse reaction of DNA polymerization where the blocked nucleotide (generally dideoxy) at the 3’ end of the primer template duplex is removed by the enzyme in presence of inorganic pyrophosphate. After the removal of the blocked nucleotide by pyrophosphorolysis, the activated primer can then be extended by DNA polymerization.
Because of the high specificity (1 / 3x1011) of PAP, this process is becoming a powerful tool for detecting rare mutations, large heterozygous deletions, gene duplications etc in the presence of a large excess of wild type allele (Liu et al : Biotechniques, 40, 661-668). In theory PAP can detect a single base mutation in 3x1011 copies of wild type allele.
PAP can be used as an alternative or to substantiate the Real Time PCR (Boon et al : Prenat Diagn 27, 932-937)
KlenTaq-S and PAP reaction.
KlenTaq-S has been found to be a suitable thermostable Taq DNA polymerase by many research groups in PAP reactions.
KlenTaq-S is expressed from 5’ deletion and F667Y (Tabor and Richardson) mutation of the gene, encoding Thermus aquaticus DNA polymerase. Repeated exposure to 980C in the PR1 reaction buffer the enzyme does not show any noticeable loss of activity.
Concentration of KlenTaq-S : 10 U/µl
Suggested Reaction Conditions for PAP (in 25 µl) :
50 mM Tris-HCl, 7.8, 16 mM Ammonium sulfate, 3.5 mM Magnesium chloride, 25 µM each four dNTPs, 0.1 µM each primer, 5-200 ng template, 90 µM inorganic pyrophosphate (Na4PPi), 2% dimethylsulfoxide (DMSO), 2.5 U of KlenTaq-S.
Cycling Conditions :
950C for 1 min (denaturation), then
940C for 15 sec
600C for 30 sec
640C for 30 sec
680C for 1 min
720C for 1-2 min total of 25-45 cycles
Buffer supplied (10X PR1):
500 mM Tris-HCl, pH 7.8, 160 mM (NH4)2SO4, 35 mM MgCl2, 1.5 mg/ml BSA
Ordering Information :
Order No. : KTS-01
Quantity : 100 µl or 1000 U/vial
Price : $200/vial (1000 U)
Shipping Charge : $35 in USA (overnight FedEx)