Chapter 13 – DNA tools and techniques

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Genetic tools (Restriction enzymes, ligases and DNA probes and primers): These tools are used as genetic scissors (restriction enzymes), genetic glue (ligases – to stick DNA fragments together) and genetic markers (probes that recognise and attach to specific sequences of DNA with a fluorescent or radioactive marker) Gene Technology video (1 of 6)  (YouTube, 9.05min)

DNA amplification: Using a Polymerase Chain Reaction (PCR) researchers can create many copies of DNA in a test tube. Access the Image Source link for a self-paced Virtual Laboratory activity that demonstrates the process of PCR using animations. Gene Technology video (2 of 6)  (YouTube, 9.54min)

Gel Electrophoresis: This technique is used to separate fragments of DNA according to their size – longer fragments with a large number of base pairs travel more slowly through the substrate (agarose gel), while shorter fragments with a smaller number of base pairs travel a greater distance. A buffer solution is added to the apparatus and DNA fragments are ‘cut’ at specific sites using restriction enzymes and loaded, together with a fluorescent dye, in ‘wells’ at the negative end of the apparatus.  An electric charge is applied and the negatively charged DNA fragments are attracted to the positive end of the gel matrix. Gel Electrophoresis on YouTube. and Gene technology (3 of 6) (YouTube, 9.41min)

DNA recombination: Scientists are able to insert fragments of DNA from one organism into another organism, bringing together genetic material from various sources. Recombinant DNA produces genetically modified organisms, that may add desirable characteristics to food crops, for example

DNA sequencing: DNA sequencing is the process of determining the precise order of nucleotides within a DNA molecule. DNA Sequencing on YouTube.  and Gene technology (4 of 6) (YouTube, 9.59min) and Gene Technology (5 of 6) (YouTube, 6.53)

DNA profiling: Also called DNA fingerprinting, this technique compares DNA from victims, suspects and crime scenes to determine which samples have the most in common. How does DNA fingerprinting work from the Naked Science Scrapbook (YouTube). 

Gene cloning: Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. Gene cloning in plain English on YouTube. 

Genetic screening: Used to identify  genetic disorders or potential risk of disease. For example, when a family has a history of females suffering from breast cancer, a genetic screening test can identify the presence or absence of a particular gene that indicates susceptibility to this cancer. Pro-active treatment may include removal of the breasts to prevent the disease. 

Genetically Modified Organisms (GMO) and transgenic organisms: When genetic engineering is used to insert specific sequences of DNA into host organisms.

Gene transformation: “In molecular biology, transformation is the genetic alteration of a cell resulting from the direct uptake, incorporation and expression of exogenous genetic material (exogenous DNA) from its surrounding and taken up through the cell membrane.” Bacterial transformation by zabaaz on YouTube.

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