Polymerase chain reaction primer annealing

Figure 3.25 Polymerase chain reaction. The steps involved in the chain reaction are as follows (i) Incubation of the DNA at a temperature above 90 °C in order to separate the two strands of the DNA duplex, (ii) Cooling of the solution to about 50 °C to allow annealing of the primers to the template (i.e. the nucleotides bind to the template DNA according to the basepairing rules), (iii) Finally, addition of the polymerase and Mg ions to extend the nucleotide primer and complete the synthesis of the complementary DNA, which takes place at about 70 °C. (iv) The sequence (i) to (iii) is repeated to allow another extension to occur many repetitions can be carried out which results in enormous multiplication of the DNA strands. NTPs - deoxyri-bonucleoside triphosphates.

Steps in the polymerase chain reaction (PCR). The DNA to be amplified is denatured and annealed with two oligonucleotides that flank the region of interest. These oligonucleotides (or primers) are extended. Extension continues to the ends of the DNA strands. The products are again denatured and annealed to primers for a second round of extension. This process of denaturation, annealing, and primer extension is repeated many times. The primary product of the reaction is duplex DNA, bounded by the sequences of the primers. (From J. L. 

Figure 4.2 Polymerase chain reaction (PCR) (Lottspeich, 1998). The PCR cycles between a denaturing step to obtain single-stranded DNA, an annealing step for the primer attachment to the template DNA, and a polymerization step, in which the heat-stable polymerase elongates the corresponding strand using the primers as starting points.

Immunocapture-polymerase chain reaction (IC-PCR) is a synthesis of two commonly used diagnostic tools. This method exploits the high-affinity binding of antibodies to provide a facile method of purification, usually from a complex matrix, supplying the substrate for PCR detection. PCR exponentially amplifies a deoxyribonucleic acid (DNA) template in a temperature-dependent fashion by the annealing of oligonucleotide primers, enzymatic extension of bound primers by a heat-stable polymerase, followed by denaturation of... 

Figure 15.5 Polymerase chain reaction step 1, separation of strands by heating (98°C) step 2, anneal primers (60°C) step 3, primer extension by polymerase.

The polymerase chain reaction uses (1) a thermostable DNA polymerase, such as Taq polymerase derived from the bacterial thermophile Thermus aquaticus, (2) a DNA template which is to be amplified, (3) two primers, each typically of around 20 nucleotides, which anneal to distinct parts on the complementary strands of the target and serve as sites for commencing DNA polymerase action, (4) a solution including the four deoxynucleoside triphosphates dATP, dCTP, dGTP and dTTP, Mg2+, salts and pH buffer. 

Figure 5-16. Principle of the polymerase chain reaction (PCR). The polymerase chain reaction relies on primer-dependent replication of a double stranded DNA template. At the beginning of the reaction, the double stranded DNA is denatured and two primers complementary to defined regions on the two strands are hybridised to the separated strands by annealing.

PCR (polymerase chain reaction) is a technique in which cycles of denaturation, annealing with primer, and extension with DNA polymerase, are used to amplify the... 

Polymerase chain reaction The method for producing, in vitro and fairly rapidly, millions of copies of a specific segment of DNA or RNA (amplification). The sequence of the ends of the portion to be copied must be known so that the primer can be annealed to the denatured oligo to be copied. An excellent source for PCR applications is www.eppendorfsi.com/application.html. 

Figure 5-47 Amplification of DNA using the polymerase chain reaction (PCR). Double-stranded DNA is denatured by heating to 90-99° C (step a) and oligonucleotide primers complementary to short 12-18 nucleotide sequences at the two ends of the piece of DNA to be amplified are annealed to the separated strands by cooling to 40 - 75° C (step b). The two DNA strands serve as templates for synthesis of new complementary strands using a heat-stable DNA polymerase and a mixture of the four nucleotide triphosphates. Nucleotide units are added to the 3 ends of the primers, with the new chains growing in the 5 3 ...

The polymerase chain reaction. Double-stranded ONA is heated to 9S"C in (he presettce of two short oligonucleotide primer sequences, each of which is complementary to the end of one of the strands. After the DNA denatures, the temperature is lowered and the primer sequences anneal to the strand ends. Raising the temperature in the presence of Tag polymerase, Mg, and a mixture of the four deoxynucleotide triphosphates (cINTP s) effects strand replication, producing two DNA copies. Each further repetition of the sequence again doubles the number of copies. 

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