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The theoretical amplification accomplished by n cycles of PCR is 2n. Starting from a single DNA segment, how much amplification would you expect to see after 20 cycles of PCR? After 30 cycles?
To determine: The amplification of a single DNA segment after 20 cycles of PCR.
Introduction: PCR, also known as, Polymerase Chain Reaction is a DNA amplification technique, which rapidly amplifies and separates DNA segments that are present in small amounts. PCR is used in DNA fingerprinting, DNA sequencing, and forensic sciences. Enzyme DNA polymerase is used in the process of PCR. The enzyme used is heat stable as PCR follows thermal cycling.
Explanation of Solution
The first step of PCR is to identify the DNA segment to be amplified. A single-stranded DNA primer complementary to the target segment is synthesized. Taq polymerase which is a thermostable DNA polymerase is added to catalyze the synthesis of the complementary DNA strand and various amplification cycles are performed to get the desired result.
The general formula for DNA amplification for n number of cycles is 2n.
The result of the amplification of a single segment after 20 cycles will be as follows:
Therefore, after 20 cycles a single DNA segment will be amplified to millions of copies.
To determine: The amplification of a single DNA segment after 30 cycles of PCR.
Introduction: PCR, also known as, Polymerase Chain Reaction is a DNA amplification technique, which rapidly amplifies and separates DNA segments that are present in small amounts. PCR is used in DNA fingerprinting, DNA sequencing, and forensic sciences. Enzyme DNA polymerase is used in the process of PCR. The enzyme used is heat stable as PCR follows thermal cycling.
Explanation of Solution
PCR begins with the identification of the DNA segment to be amplified and is followed by the synthesis of a single-stranded artificial primer complementary to the DNA segment which needs to be amplified. DNA polymerase called Taq polymerase is then added to add nucleotide sequences and synthesize the complementary strand. This process is repeated over n number of cycles in order to achieve the desired results.
The amount of copies produced after n number of cycles is given by the formula 2n.
The result of the amplification of a single segment after 30 cycles will be as follows:
Therefore, after 30 cycles a single DNA segment will be amplified to billions of copies.
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Chapter 17 Solutions
Becker's World of the Cell (9th Edition)
- Explain why a positive control and negative control are included in PCR experiments. Explain the three steps involved in each cycle of polymerase chain reaction.Why is loading dye added to the DNA sample for gel electrophoresis? Explain the function of the following components in a PCR reaction:− Primer, dNTP, MgCl, Taq polymerase, buffer.arrow_forwardYou are performing PCR for the first time using some new primers that are 25 nucleotides in length with an estimated melting temperature of 65 0C to amplify a 200 nucleotide gene. After PCR, you run an agarose gel on the samples and observe a faint band at 25 nucleotides. What is the best possible explanation for the results? The primers hybridized to multiple sites on the DNA template. Too much template DNA was added to the PCR mixture. The primers dimerized preventing DNA transcription from occurring. A nuclease was in the solution causing degradation of the DNA.arrow_forward(A) After three cycles of PCR, how many DNA molecules are present that correspond precisely to the desired amplification product? (B) What about after 5 cycles. Assume that we started with one molecule in each case, and that the reaction is perfectly efficient.arrow_forward
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- The exponential nature of PCR allows spectacular increases in the abundance of a DNA sequence being amplified. Consider a 10-kbp DNA sequence in a genome of 1010 base pairs. What fraction of the genome is represented by this sequence; i.e., what is the fractional abundance of this sequence in this genome? Calculate the fractional abundance of this target sequence after 10, 15, and 20 cycles of PCR, starting with DNA representing the whole genome and assuming that no other sequences in the genome undergo amplification in the process.arrow_forwardYou are working in a molecular biology laboratory and are having challenges with your PCR. You decide to double-check the PCR protocol programmed into the thermal cycler and discover that the annealing temperature was programmed to be 65 °C instead of 50 °C, as you had intended. What effects would this mistake have on the PCR reaction? Suggest potential solution(s).arrow_forwardAfter four cycles of PCR, which type of PCR product predominates? Explain why.arrow_forward
- After four cycles of PCR, which products predominate? Explain why.arrow_forwardPolymerase Chain Reaction (PCR) was invented by Kary Mullis in 1983. This technique had indeed facilitated research in various areas of molecular biology and genetics. You would like to amplify a particular gene fragment from the yeast genome using Polymerase Chain Reaction (PCR). What are the THREE (3) main cycles in PCR? Discuss the processes at each PCR cycle mentioned.arrow_forwardAn analyst designed a pair of primers to detect the presence of Alu sequence in human DNA genome extract. The forward and reverse primers have the melting temperature at 70 and 50 Celsius degree respectively. Will the PCR work with the following PCR condition? Denaturing: 95 C for 1 min Annealing: 55 C for 1 min Extension: 72 C for 2 min Cycling: 35 cycles Yes. Annealing temperature at 55 is a standard in PCR. Yes. Difference in meting temperature of primer pair does not affect PCR. O No. There is chance that one of the primer won't anneal to the correct sequence. O No. DNA polymerase does not work at 72 Celsius degree.arrow_forward
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