Elizabeth+Leonhardt

__﻿__ DNA Cloning/Recombinant DNA/Genetic Engineering
__** Gene Cloning with Bacterial Plasmids **__ //Description and Analysis//: Plasmids, which are circular fragments of bacteria DNA that are separate from the chromosome, are spliced with a gene from a different type of cell. The plasmid is then put back in the bacteria it came from. When the bacterium reproduces, it clones both its DNA and the recombinant bacteria. //Application//: Cloned genes can be used to make copies of a certain gene or make lots of a certain protein product. That way, a gene that makes plants resistant to bugs can be made part of a different plant or a certain hormone can be made in mass amounts. //My thoughts on it//: I think it would be really cool if bacteria could be modified with this technique to make people healthy instead of sick. Maybe a plasmid could be modified so it at least counteracted the negative effects of the bacteria it was part off. //Why is it important//: This is a useful method cloning certain genes and is important because it is a way gene libraries are be made. Learn More At:[]

__**Nucleic Acid Hybridization **__ //Description and Analysis//: Genes form hydrogen bonds with complementary sequences of nucleic acid. When the complementary strand is made radioactive it can be traced, identifying a both the strand (a nucleic acid probe) and the target DNA it bound to. //Application:// Hybridization makes it possible to find a certain gene out of an entire colony. //My thoughts on it//: This method reminds me of using magnets to find lost screws and nails. The gene probe finds and connects to the right gene out the masses like a strong magent finds and picks up hidden bits of metal out of the dirt. //Why is it important//:This is a necessary method to find a certain gene or find similar genes. Learn More At: []

__** Genomic Library **__ //Description and Analysis//: A genomic library is a set of plasmid-containing cell clones. Each clone has copies of a particular bit of the original foreign DNA. A complete library has the entire genome of the original DNA, each piece in its own plasmid and organized by vector. // Application: // Once a genomic library is created, every gene in it can be found and studied individually. //My thoughts on it//: It can be used to research the genome of plants and animals that are rare or even extinct without doing anything to the organisms themselves. //Why is it important//: Genomic libraries are an important research tool when studying certain genes and they can be used to create more clones of a gene. Learn More At:[]

__**Polymerase Chain Reaction (PCR) **__ //Description and Analysis:// This is a process where many copies of a specific segment of DNA using a PCR Reaction. Copies are made using heat to separate the double stranded DNA in a process called denaturation. Then in annealing, the DNA is allowed to cool so that primers targeted on the specific segments can bond. Then in the last stage, a heat resistant polymerase creates the complementary segment of DNA. After 3 cycles, a fourth of the DNA copies are exactly what was wanted. //Application:// By using PCR, scientist can create many copies of a gene without having to first create a sort through an entire genomic library. //My thoughts on it//: This is like flipping to the right page in a book and writing down your favorite quote instead of buying the whole book. //Argument for it//: This is much more practical and much faster than always creating genomic libraries. Learn More At: []

__Gel Electrophoresis __
//Description and Analysi//s: Gel Electrophoresis is a method that uses a gel made of a polymer, combined with electricity, to separate the molecules of a section of DNA. A tray is filled with an aqueous soltion and a sheet of the gel is immersed inside the solution. The tray itself is connected to a power source, with one end of the tray as the negative cathode and the other end as the positive anode. Electric current moves through the tray, solution, and gel. The gel has little hollows called wells in a line by the cathode end. DNA is cut and its fragments are placed in one of the hollows and when the current is turned on, the negatively charged DNA moves toward the positive anode end. Since the longer molecules have a harder time making thier way through the web of polymers that make up the gell, they move more slowly than the shorter polymers. Once the current is turned off, a special dye is added to make the DNA visible. The gel will have bands where certian molecules were forced to stop. Each type of DNA has its own pattern of bands. //Application:// Gel electrophoresis is a good way to find variations and muations in genes, as even little changes in the DNA show up as changes in the band pattern. //My thoughts on it: This reminds me a lot of chromatograpghy. Instead of dye componentes being separated by water, DNA components are being separated by gel and electricity. // // Argument for it: // This is a good way to study small pieces of DNA but longer fragments have som many sections that they blot instead of creating lines. It is still a very useful tool.

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<span style="color: #d80ec6; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: Southern Blotting is basicly gel electrophoresis with nucleic acid probes. Since larger sections of genomic DNA have to many bands, which form a blot, radioactive probes are added to identify the targeted segements. First, electrophoresis does its work, then the DNA is transfered to nitrocellulose paper by letting an alkaline solution soak up through the gel and into the paper, carying the DNA fragments with it. That is called blotting. Then the probe is added. The probe highlights only the target degments so only the bands with that DNA show up. ===== <span style="color: #b600ff; font-family: 'Comic Sans MS',cursive;">//Application//: This can be used to see if the DNA taken from a crime sceen matches that of suspect or to see how geneomes are slightly different from person to person. <span style="color: #d80ec6; font-family: 'Comic Sans MS',cursive;">//My thoughts on it//: Using Southern Blotting with cancer cells could show just how the cells are different from healthy cells and maybe shed some light onthe kind of mutation that causes cancer. <span style="color: #d80ec6; font-family: 'Comic Sans MS',cursive;">//Argument for it//: This is a way to study certain genes without having to use plasmids to seperate and identify them first.

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<span style="color: #0b1cd5; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: Microarrays are tiny slides with large amounts of DNA. One by one, single strands are fixed to organized spots. Then single stranded florescent cDNA is added to the top of the tray. The cDNA binds to any complementary strands of DNA and a scan will show the places were strands are bound and expressing the gene. By studying the patterns, scientist can find the level of expression for each gene. ===== <span style="color: #2379f6; font-family: 'Comic Sans MS',cursive;">//Application:// Microarrays show the level of gene expression in cells and how it changes during development. It is a great way to see how genes interact and function, which in turn can be used to make better medical treatments. <span style="color: #0b1cd5; font-family: 'Comic Sans MS',cursive;">//My thoughts on it//: This could be used to see how the genes in skin cells are expressed in a healthy person and how they are expressed in a person with skin cancer. Maybe a way could be found to force some genes to express themselves in ways that would make skin more resistant to cancer. <span style="color: #2379f6; font-family: 'Comic Sans MS',cursive;">//Argument for it:// This process show the epxpression of thousands of genes at once, as opposed to one or two genes at a time. <span style="color: #2379f6; font-family: 'Comic Sans MS',cursive; line-height: 0px; overflow: hidden;"> Learn More At:[]

<span style="color: #f01414; font-family: 'Arial Black',Gadget,sans-serif;">Cloning Organisms
__** Plant Cloning **__ <span style="color: #0b1cd5; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: Simply growing a plant from a cutting is cloning it, because the cutting will frow into a plant with DNA identical to the one it came from. But plants can also be cloned from a single plant cell. A non-reproductive, fully differentiated cell can be cut from a plant and, once placed in a nutrient medium, grow into an embryo. The embryonic plantlet is grown in an agar medium and then in the ground, forming a full grown adult plant with DNA identical to its parent. <span style="color: #0b1cd5; font-family: 'Comic Sans MS',cursive;">//Application//: Using single cell cultures to clone plants can mean one perfect plant becoming a feild of perfect plants. Many flowers are so hard to grow that cloning them is the only way to produce them in large amounts. <span style="color: #0b1cd5; font-family: 'Comic Sans MS',cursive;">//My thoughts on it//: Hybrid plants could be cloned and not lose any of their special genetic qualities, because there would be no cross pollinization. <span style="color: #0b1cd5; font-family: 'Comic Sans MS',cursive;">//Argument for it//:This is increadible becasue it takes an ordianry cell and turns it into an adult plant. It is a great way to mass produce certain crops and flowers. Learn More At: []

__** Animal Cloning **__ <span style="color: #f01414; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: In animal cloning the nucleus of a cell is placed in an egg cell that had its nucleus removed. The transplanted nucleus can be taken from the embryo of an organism and the egg grows into an adult. If the animal being cloned is a mammal, the donated nucleus can be taken from mammary cells that have been induced to revert to dedifferentiation. The recombinant cell is grown in a culture and if once it reaches the early embryo stage it is implanted into a surrogate mother. If all goes well, the embryo continues to develop until it is full grown. <span style="color: #f01414; font-family: 'Comic Sans MS',cursive;">Application: Animals can be cloned, even animals that are endagered or rare. Animals with certain genetic traits can have offspring garunteed to have those traits. <span style="color: #f01414; font-family: 'Comic Sans MS',cursive;">My thoughts on it: This could be used to put healthy genes into an organism that has negative genes. Hopefully, the gene could be used to counteract the problems from the harmful traits the organism has. <span style="color: #f01414; font-family: 'Comic Sans MS',cursive;">Argument for it: This can be used to clone or "design" a specific type of animal but most embryos do not make it to full development and those that do have health problems or defects. It has great possiblities but needs work. <span style="color: #f01414; font-family: 'Comic Sans MS',cursive;">Learn More At: [] =Practical Application of DNA Technology=

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<span style="color: #1ea91e; font-family: 'Comic Sans MS',cursive;">//Description and Analysis:// RFLPs are single base-pair sequence changes. The change alters where resitriction enzymes cut the fragments so the fragments have different sizes. RFLPs are close to certain alleles for genetic disorders. Since they are so close, they rarely cross over during meiosis, so RFLPs can ussually be found near the alleles they mark. It is possible to discover a bad allelle by looking for a certain RFLP. PCR or microarray analysis can find RFLPs quickly, making the process much easier. ===== <span style="color: #008000; font-family: 'Comic Sans MS',cursive;">//Application:// By finding markers, it is possible to test for genetic diseases like Huntingtons. Using this method is a good way to find out if someone is a carrier for a disease. <span style="color: #1ea91e; font-family: 'Comic Sans MS',cursive;">//My thoughts on it//: This is like using sticks to show where seeds have been planted. The sticks are visible and mark where the seeds were buried in the same way RFLPs can be detected and show where certain alleles are. The only difference is that RFLPs occur naturally. <span style="color: #008000; font-family: 'Comic Sans MS',cursive;">//Argument for it//: Testing for RFLPs is more practical than testing for a disease causing allele itself. It can also test if someone is a carrier for a genetic disease even though they never have the symptoms themselves. <span style="color: #008000; font-family: 'Comic Sans MS',cursive;">Learn More At:[]

__<span style="color: #b600ff; font-family: 'Comic Sans MS',cursive;">Gene Therapy __
<span style="color: #b600ff; font-family: 'Comic Sans MS',cursive;">//Description and Analysis:// Gene therapy gives an organism that is missing an or has a mutated allele the correct allele by implanting it into some of that person's DNA. Safe viral DNA is given the good allele. Then the recombinant retrovirus insterts the good allele into cells taken from the organism. Then the cells are injected back into the organism. If the new gene expresses itself, then the organism is cured. This works best when all that is wrong is a single gene. <span style="color: #ff00ff; font-family: 'Comic Sans MS',cursive;">Application: Gene therapy can treat patients with health problems caused by missing or mutated genes <span style="color: #b600ff; font-family: 'Comic Sans MS',cursive;">My thoughts on it: This could be used the help diabetes patients by giving them the genes they need to produce insulin. <span style="color: #ff00ff; font-family: 'Comic Sans MS',cursive;">Argument for it: Gene therapy can make a huge difference but it is dangerous to mess with an organisms genome and there are some ethical issues over implanting DNA. It is still a potentially wonderfully treatment. <span style="color: #ff00ff; font-family: 'Comic Sans MS',cursive;">Learn More At:[]

__<span style="color: #1ea91e; font-family: 'Comic Sans MS',cursive;">Transgenic Animals (Genetically Modified Organisms~GMOs) __ <span style="color: #1ea91e; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: Transgenic Animals are classified as GMOs, genetically modified organisms, because they have at least one artificially gained trait that came from another species or a different version of the same species. They are usually made by fertilizing an egg in vitro and adding the new gene to the nucleus of the egg. The egg is then surgically placed in a surrogate mother. The animal that results the new gene as part of the genomic DNA. <span style="color: #377737; font-family: 'Comic Sans MS',cursive;">//Application:// By putting human genes into animals, those transgenic animals can produce milk and eggs high in the protein that gene produces. It is easier to refine the protein from that product and give it to humans than it is to refine it from cultured cells. Another application is creating animals that have resistance to disease or a better tolerance for certain conditions. <span style="color: #1ea91e; font-family: 'Comic Sans MS',cursive;">My thoughts on it: Trangenic animals could have some really amazing combinations, like butterflies that have the color changing gene or leopards with strips instead of spots. <span style="color: #008000; font-family: 'Comic Sans MS',cursive;">Argument for it: This method would be a great way to gain much needed proteins from easy sources. Even with the small differences from modification, the proteins can be refined and tested until they are ready for human use. As long as the animals are treated well and not hurt by the meddling with their genes, it could be a wonderful tool. Learn More At: [] __<span style="color: #510080; font-family: 'Comic Sans MS',cursive;">Transgenic Plants (GMOs) __

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<span style="color: #510080; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: Transgenic Plants, which are genetically modified organisms (GMOs), are plants that have one or more genes from another species of plant or another type of plant from the same species. Instead of gaining those genes by cross breeding, they were artificially modified. These plants can be anything from cotton that is resistant to bugs to rice that has extra vitamin A. Often, such plants are made from Ti plasmids, which can be directly added to plant cells or put back in bacteria to infect the plant with a retrovirus that adds the DNA to the plants genome. ===== <span style="color: #800080; font-family: 'Comic Sans MS',cursive;">//Application//: The transgenic plants can be engineered to be better suited to new environments, to be healthier, to produce more, or simply change the color of flowers. <span style="color: #510080; font-family: 'Comic Sans MS',cursive;">//My thoughts on it//: Transgenic plants remind me of processed foods, with extra ingredients added before the plant is even grown. <span style="color: #b600ff; font-family: 'Comic Sans MS',cursive;">//Pros and Cons:// Plant GMOs are given new and usually beneficial traits, but those new traits could turn into a bad thing or trigger other traits that are not so much fun. Imagine a plant so strong it chokes out all the other plants and can not be killed. Or a glitch caused by adding a new gene; a glitch that makes apples or sugar toxic. Learn More At:[]

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<span style="color: #0000ff; font-family: 'Comic Sans MS',cursive;">//Description and Analysis//: A genetic profile is the individual set of markers and STRs (Short Tandem Repeats- the repeated units of a base pair in a specific part of the genome). Scientists can compare the unique number of STRs in a section to the number another person has in the same section. By checking at least 13 markers, it is possible to determine exactly which person the sample came from. =====

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<span style="color: #2379f6; font-family: 'Comic Sans MS',cursive;">//Application//:By checking the number of STRs a person has in a certain part of their genes and comparing it to evidence from crime scenes, investigators can match DNA from far few amounts of DNA than other techniques. It can also be used to check if certain people are related, since profiles are similar in family members. ===== <span style="color: #0000ff; font-family: 'Comic Sans MS',cursive;">//My thoughts on it:// This is like comparing fingerprints except it is easier to get clear evidence with genetic profiles. <span style="color: #6095e1; font-family: 'Comic Sans MS',cursive;">//Argument for it:// This is a great way to check identities and match evidence to suspects.

Learn More At: http://asiabiomed.wordpress.com/category/biotechnology/

Sources: Campbell Reece AP Edition Biology book, http://asiabiomed.wordpress.com/category/biotechnology/