• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Polymerase Chain Reaction

Extracts from this document...

Introduction

Polymerase Chain Reaction "Investigate what PCR is - how has it revolutionised molecular biology and give several examples of how it is used?" PCR stands for polymerase chain reaction. This is a technique devised by Cary Mullis for cloning genes in a test tube without involving bacteria - and instead uses DNA polymerases (enzymes) to make multiple copies of a DNA strand. The polymerases must be able to function at high temperatures, so the enzymes are usually obtained from thermophilic bacteria such as Thermus aquaticus. To obtain the DNA, the sample of cells is placed into a solution, and solution is boiled, so the DNA is released. The DNA to be copied is placed in solution, and the temperature of this solution is then raised to 95?c to separate the two strands of DNA. ...read more.

Middle

sequentially to each strand, forming two new strings of DNA that complement the originals. Repetition of these steps doubles the amount of DNA present after each iteration. The proper experimental conditions induce these constituents to assemble two new copies from what was originally one DNA molecule. The steps involved take just a few minutes. And repeating the procedure doubles the number of copies each time. So 30 cycles of PCR produce a billion-fold increase of the targeted section of DNA, "amplifying" what might begin as a single molecule into enough material for easy examination. PCR enables DNA profiling to be used successfully on very small tissue samples, such as spots of blood, hair roots or a small semen stain. ...read more.

Conclusion

Robert Melias in 1987 was the first person to be convicted of a crime on the basis of evidence including DNA profiling. DNA profiling is now used in many thousands of criminal investigations each year. PCR can be used to help DNA profiling for these uses: detecting inherited diseases in embryonic cells, resolving paternity disputes, checking immigration applications, confirming animal pedigrees, and establishing genetic relationships between humans preserved in archaeological sites, such as peat bogs, etc, and people alive today. PCR is a very useful way of replicating DNA without the use of bacteria. It can be used for many different purposes, but its main use is in different crime cases, where only a very small amount of DNA has been left at the scene of the crime. It has been used very successfully thousands of times to correctly convict suspects of crimes they have committed. ?? ?? ?? ?? ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Genetics, Evolution & Biodiversity section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Genetics, Evolution & Biodiversity essays

  1. Marked by a teacher

    An Investigation into the Mitotic Nuclear Division of Allium Sativum Root Tip Cells, and ...

    5 star(s)

    that depart from the concepts that are described and explained throughout the hypothesis, analysis and therefore background information concerning the reasons for the relative lengths of the stages of mitosis. Students 2 and 4 appear to have obtained results that contradict the trend expressed by the other students; the data provided for the stages telophase and metaphase are essentially reversed.

  2. Peer reviewed

    An Investigation into the effect of caffeine on reaction times

    5 star(s)

    Controlled variables Factor How I will prevent it How it would affect my results How the error would be visible in my results What kind of error Improving at the games I have decided that I cannot prevent this factor within the time that I have The results would improve

  1. Chromosomes and DNA

    This exercise will remind you how nitrogen is converted into different forms before being used and excreted by plants and animals. Nitrogen must be changed into a more reactive form to allow plants and animals to use it. Plants can take up and use nitrogen when it is in the form of nitrates or ammonium salts.

  2. The Progression of Genetics from Gregor Mendel to Polymerase Chain Reaction

    At this point in scientific history theories were combining to piece together the fundamentals of living organisms. (4) (5) The next two decades saw experimentation in order to further understanding of genetics, including the first case of transformation as Frederick Griffith showed the uptake and expression of foreign DNA in bacteria in 1928.

  1. Defense in the blood

    Therefore my argument, that the system is irreducibly complex, is unaffected by that example. b. Gene Duplication is not a Darwinian Explanation I believe that the point about the knockout mice is quite important because it helps illustrate the serious shortcomings of simple invocations of gene duplication as evolutionary explanations.

  2. Explain how DNA fingerprinting works.

    Next, DNA pieces need to be transferred to a nylon sheet. This is done by placing the sheet on the gel with the distribution of DNA and soaking them overnight. Adding radioactive or colored probes to the nylon sheet produces a pattern called the DNA fingerprint.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work