Preview

Dna Digestion and Electrophoresis

Good Essays
Open Document
Open Document
712 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Dna Digestion and Electrophoresis
DNA DIGESTION AND ELECTROPHORESIS
In this experiment we will be doing a process called as DNA digestion or also known as restriction digest. A restriction digest is a procedure used in molecular biology to prepare DNA for analysis or other processing. It is sometimes termed DNA fragmentation, scientists Hartl and Jones describe it this way:
This enzymatic technique can be used for cleaving DNA molecules at specific sites, ensuring that all DNA fragments that contain a particular sequence have the same size; furthermore, each fragment that contains the desired sequence has the sequence located at exactly the same position within the fragment. The cleavage method makes use of an important class of DNA-cleaving enzymes isolated primarily from bacteria. These enzymes are called restriction endonucleases or restriction enzymes, and they are able to cleave DNA molecules at the positions at which particular short sequences of bases are present.
The resulting digested DNA is very often selectively amplified using PCR, making it more suitable for analytical techniques such as agarose gel electrophoresis, andchromatography. It is used in genetic fingerprinting, and RFLP analysis. [1]

Just as mentioned above, for this experiment we will be using restriction enzymes. Restriction enzymes or restriction endonuclease are enzymes isolated from bacteria that recognize specific sequences in DNA and then cut the DNA to produce fragments, called restriction fragments. They play a very important role in the construction of recombinant DNA molecules, as is done in gene cloning experiments. [2]
Restriction endonucleases such as EcoRI recognize specific palindromic sequences and cleave a phosphodiester bond on each strand at that sequence. After digestion with a restriction endonuclease the resulting DNA fragments can be separated by agarose gel electrophoresis and their size can be estimated. A restriction map is generated by using the fragment size data to determine the location

You May Also Find These Documents Helpful

  • Better Essays

    Nt1310 Unit 1 Exercise 1

    • 1475 Words
    • 6 Pages

    Denaturation is carried on by heating the double-stranded DNA at 94°C to separate the complementary strands that will serve as template in further cyclings. Pre-denaturation is sometimes done at the same temperature to ensure complete separation of strands. Annealing then occurs upon rapid cooling of the solution, allowing oligonucleotide primers to hybridize to the template. In this phase, however, the single strands of the template are too long and complex to be able to completely reanneal spontaneously. The gene fragment to be amplified will completely form double-stranded fragments upon further cycling of this step and the extension step. The extension step involves heating of the reannealed DNA to 72°C, the temperature at which the thermostable DNA polymerase in the mix will operate most efficiently in synthesizing new DNA strands.…

    • 1475 Words
    • 6 Pages
    Better Essays
  • Better Essays

    Apush Unit 5 Review

    • 1238 Words
    • 5 Pages

    The purpose of this lab was to observe the different amount of distances each DNA samples travel when placed in a gel-electrophoresis box. Restriction endonucleases are critical tools in recombinant DNA methodology. Electrophoresis is the method of determining the size of fragments that are cut by restriction enzymes. These restriction enzymes always cut at their specific protein recognition sites. This is very useful in the sense that no two restriction enzymes codes for exactly the same recognition site, giving it a unique characteristic that is specific for a strand of DNA. Gel electrophoresis is a technique used to separate different sized fragments of DNA or RNA with the use of an electric field. When a molecule enters an electric field, the speed at which the molecule moves is influenced by several factors including: the charge of the molecule, the strength of the electrical field, the size and shape of the molecule, and the density of the medium (in this case the agarose gel) through which the molecule moves. Because of this, scientists are able to separate different groups of DNA or RNA molecules by first positioning all the molecules at a uniform starting point on the agarose gel and then placing the gel in a chamber containing buffer solution and electrodes. A buffer is a solution that adds extra ions to the gel enhancing the conductivity in the agarose gel matrix. Once in the chamber containing buffer solution and electrodes, the molecules of DNA will begin to migrate through the gel and form bands due to the negative charge of the phosphate groups in the backbone of DNA moving towards the positive electrode.…

    • 1238 Words
    • 5 Pages
    Better Essays
  • Good Essays

    AP Bio Ch. 20 Vocabulary

    • 538 Words
    • 2 Pages

    3. Restriction enzyme – A degrading enzyme that recognizes and cuts up DNA (including that of certain phages) that is foreign to a bacterium.…

    • 538 Words
    • 2 Pages
    Good Essays
  • Good Essays

    of genomic DNA that has been cut with restriction enzyme X. The gene you wish to insert has…

    • 4889 Words
    • 20 Pages
    Good Essays
  • Powerful Essays

    Sq3r Chapter 13

    • 1466 Words
    • 6 Pages

    4) EcoRI is a restriction enzyme that is used widely by scientists. EcoRi specifically cuts DNA containing the sequence GAATTC. The ends of the DNA fragments created by ECORI are called sticky ends because they contain single-stranded DNA that is complementary.…

    • 1466 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    Brandon Schmetterer 3-13-15 Biology labs DNA Extraction Lab DNA is extracted from humans for genetic testing, for body identification, and for analysis of forensic evidence. The first step of DNA extraction is to take cheek cells from the test subject. Next, the cells must be burst open in order to release DNA. Third, DNA is separated from protein and debris. Lastly, the DNA must be isolated.…

    • 509 Words
    • 3 Pages
    Good Essays
  • Powerful Essays

    Chapter 10 Gene Technology

    • 2264 Words
    • 10 Pages

    When RNA polymerase makes an unprocessed mRNA copy of DNA, the copy is called the ___________________.…

    • 2264 Words
    • 10 Pages
    Powerful Essays
  • Powerful Essays

    In PBS, you learned about the molecular biology techniques that allow scientists to explore our DNA. PCR, Polymerase Chain Reaction, is the copy machine; the revolutionary process that allows scientists to replicate even the tiniest speck of DNA. Restriction endonucleases (enzymes) are the molecular scissors that can cut DNA in specific locations. Your specific code determines the number of times this set of scissors will snip and the number and size of DNA pieces that will be left behind. These pieces can then be separated and compared using the process of gel electrophoresis. As these fragments move, their varying lengths propel them through the gel at different speeds. Scientists can use these RFLPs, Restriction Fragment Length Polymorphisms, a set of DNA puzzle pieces unique to only you, to create a pattern called a DNA fingerprint. Similar to the unique…

    • 1747 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    An individual’s code determines the number of times the restriction enzymes will cut and the number and size of DNA pieces that will result. These pieces can then be separated and compared using a process called gel electrophoresis. The DNA moves from the negative end to the positive end. As the fragments move, their varying lengths propel them through an agarose gel at different speeds. Short strands move through the holes in the gel more quickly than long strands and will over time move farther away from the starting point. Staining the sorted groups of DNA makes them visible to the naked eye (show up as bands in the…

    • 1489 Words
    • 6 Pages
    Good Essays
  • Better Essays

    Lab Report Part II

    • 1247 Words
    • 4 Pages

    Background Information: The process begins with preparing a sample. Successful identification starts with using a sample that is considered to be good. The first step is to pick up a single colony and drop it into a microcentrifuge tube. A buffer is used to dissolve the cell wall in order to extract bacterial DNA. This step may take several hours. The proteolytic enzymes need to go before proceeding. Heating the sample in a water bath at 100 degrees Celsius denatures them. Next, cellular debris is spun down in the centrifuge and appears as a pellet at the bottom. The DNA is contained in the liquid, which is then transferred to the tube. To continue the process, PCR amplification is conducted. One must add PCR Master Mix solution to the sample DNA to prepare the polymerase chain reaction. The mix contains water, a buffer to keep the correct pH for the reaction; large quantities of the four nucleotides; large quantities of oligonucleotide DNA primers; and a heat-stable DNA polymerase. At the same time, one will prepare negative and positive control reactions. The positive contains positive control DNA while the negative contains sterile deionized water. Both contain the PCR solution. Once reaction tubes have been loaded onto the PCR machine, DNA replication starts. By doing this, one can know temperature, time remaining, cycle number, melt, anneal, and extend. The first step, melt, is to separate the two DNA chains in the double helix by heating the vial containing the PCR reaction mixture to 95 degrees Celsius for 30 seconds. The vial is cooled at 60 degrees Celsius. The final step, extend, is to allow the DNA polymerase to extend the copy DNA strand by raising the temperature to 70 degrees Celsius for 45 seconds. Separation of the strands, annealing the primer to the template, and the synthesis of new strands…

    • 1247 Words
    • 4 Pages
    Better Essays
  • Better Essays

    2. Restriction enzymes are made by bacteria to cut up invading DNA. They target specific base sequences in the DNA and then work to cut out those sequences from the DNA.…

    • 1001 Words
    • 5 Pages
    Better Essays
  • Satisfactory Essays

    PLTW 1.2.2

    • 431 Words
    • 2 Pages

    It’s a technique that amplifies DNA by making a perfect temperature for primers and enzymes to make copies. With the millions of copies you have you can then code the DNA to figure out it’s sequence.…

    • 431 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    1.3.1 response

    • 620 Words
    • 3 Pages

    Visit the list of restriction enzymes found at the bottom of the page on http://en.wikipedia.org/wiki/Restriction_enzymes. Find the unique sequence (restriction site) that is recognized by EcoRI and by HindIII. Write the double-stranded sequence below and draw an arrow between the base pairs to indicate where the enzyme would make its cut.…

    • 620 Words
    • 3 Pages
    Satisfactory Essays
  • Good Essays

    Forensic

    • 420 Words
    • 2 Pages

    Restriction Fragment Length Polymorphism is a method used to study DNA. One of the reasons that this test became less useful is because it requires an excessive amount of DNA.…

    • 420 Words
    • 2 Pages
    Good Essays
  • Best Essays

    Title: Cloning of Enhancer of Zeste Homolog 2 in forward orientation into Escherichia Coli using histidine-tagged pbluescript II KS+.…

    • 4373 Words
    • 18 Pages
    Best Essays