The unique property of nucleic acids to pair with each other through complementary base pairing is the lifeblood of genetic engineering. A single strand of DNA can pair up with another strand of DNA or RNA if its base pairs are complementary to those of the other strand, under the right conditions of temperature and pH. This phenomenon is called nucleic acid hybridisation. It is possible to exploit this mechanism for the detection of one nucleic acid strand from a mixture of many other strands. For instance, if a DNA strand with a desired nucleotide sequence is to be detected from a mixture of many other strands, an oligonucleotide containing a few complementary bases to the desired sequence can be prepared and attached to an anchor such as a membrane or a paper. When soaked in a solution having a mixture of many strands, the one, which is complementary to the oligonucleotide, will bind to it through complementary base pairing, also known as “zippering” (Lodish et al, 2004, p. 11).
When double stranded DNA is heated in a dilute salt solution, its two strands separate because of the breakdown of complementary base pairing (melting). This strand separation is called denaturation. The temperature at which the two complementary strands separate is called the melting temperature ‘Tm’, and is affected by the percentage of G.C base pairs, ion concentration of the solution, presence of destabilising compounds like urea, and the pH of the solution (Lodish et al, 2004, p. 105).
Nucleic acid...
... middle of paper ...
...ected to a probe. These techniques can be used to distinguish between alleles that vary even by single nucleotides (“Nucleic acid hybridization assays”, 1999, Ch. 5).
Nucleic acid hybridisation is used in many routine experiments in the molecular biology laboratory, making it an indispensable requirement in genetic engineering and molecular biology.
Works Cited
“Fluorescent Probes”, n.d. piercenet.com. Retrieved August 2, 2011 from http://www.piercenet.com/browse.cfm?fldID=4DD9D52E-5056-8A76-4E6E-E217FAD0D86B
Lodish, H. et al., 2004. Molecular Cell Biology. W. H. Freeman, New York.
“Nucleic acid hybridization assays”, 1999. Retrieved August 2, 2011 from http://www.ncbi.nlm.nih.gov/books/NBK7567/
Nussbaum, R. L., 2004. Thompson and Thompson genetics in medicine. Elsevier Health Sciences, n.a.
Recombinant DNA technology: Sub cloning of cDNA molecule CIH-1 into plasmid vector pUC19, transformation of XLI-Blue Ecoli & restriction mapping.
The main goal for our experiment was to learn how to examine DNA when there is only a small
"Fluorescence in Situ Hybridization (FISH) Fact Sheet." National Human Genome Research Institute. 15 Nov. 2007. National Institutes of Health. .
Paul Berg created the first recombinant DNA molecule by combining genes from different organisms. Recombinant DNA is a DNA molecule created by joining various DNA seque...
In order to do this a polymer of DNA “unzips” into its two strands, a coding strand (left strand) and a template strand (right strand). Nucleotides of a molecule known as mRNA (messenger RNA) then temporarily bonds to the template strand and join together in the same way as nucleotides of DNA. Messenger RNA has a similar structure to that of DNA only it is single stranded. Like DNA, mRNA is made up of nucleotides again consisting of a phosphate, a sugar, and an organic nitrogenous base. However, unlike in DNA, the sugar in a nucleotide of mRNA is different (Ribose) and the nitrogenous base Thymine is replaced by a new base found in RNA known as Uracil (U)3b and like Thymine can only bond to its complimentary base Adenine. As a result of how it bonds to the DNA’s template strand, the mRNA strand formed is almost identical to the coding strand of DNA apart from these
States. The FBI performs testing for free to all police agencies to help keep costs down
To form a polynucleotide DNA, many nucleotides are linked together with 3`-5` phosphodiester linkages. In a compl...
Each of the nucleotides accommodate a phosphate group, sugar group, and a nitrogen base. There is four nitrogen bases in DNA. The four nitrogen bases are; Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). Each of the bases are connected to a sugar molecule and a phosphate molecule. They are then positioned into two long strands that form a spiral called a double helix (DNA). The nitrogen bases are paired up with one another. Adenine and Thymine will always be paired with each other because of the bonds between them. Between A and T, there are two hydrogen bonds. The same goes with Guanine always being paired with Cytosine due. Between both G and C there is three hydrogen bonds. The nitrogen bases Adenine and Guanine won’t pair up with each other because, of their size. Both the nitrogen bases Adenine and Guanine are a purine base. Thymine and Cytosine are both a pyrimidine base. Adenine pairs with Thymine, and Guanine pairs with Cytosine, because they are of opposite
We were able to examine the DNA or RNA by placing the contents in an agarose gel buffers utilizing an electric charge. The process uses restriction enzymes which cut DNA at restriction sites. The process pushes negatively charged particles to the positive pole.
The G-rich and C-rich DNAs individually form the parallel G-quadruplex and I-motif, respectively, in the molecular crowding condition, and the 1:1 mixture folds into the parallel G-quadruplex and I-motif but does not form a duplex. The ITC measurements indicated that the thermodynamic stability (ΔG°20) of the duplex formation between the G-rich and C-rich DNAs in the noncrowding condition was −10.2 kcal mol-1, while only a small heat change was observed in the ITC measurements in the molecular crowding condition. These ITC results also demonstrated that the molecular crowding condition prevents any duplex formation between G-rich and C-rich DNAs. These results indicate that a structural polymorphism of the telomere DNAs is induced by molecular crowding in vivo [25]
This discussion was aimed to observe and measure DNA molecules. Because of negative charge, DNA migrates towards the positive electrode (anode). Hence, the cathode must be placed on the side close to the contained sample wells, whereas the anode placed on the opposite position. And approximate of 100V is provided to the system, DNA molecules keep migrating until the dyes reach the end of the gel. After electrophoresis, use Ethidium Bromide (C21H20BrN3), which links with DNA molecules and fluoresces under ultraviolet (UV) light to observe the DNA fragments on the gel. Photographing the lit gel under ultraviolet light in a dark room to record the result.
Watson, J. D., Gilman, M., Witkowski, J., Zoller, M. (1992). Recombinant DNA. New York: W. H. Freeman and Company.
The scientific and medical progress of DNA as been emense, from involving the identification of our genes that trigger major diseases or the creation and manufacture of drugs to treat these diseases. DNA has many significant uses to society, health and culture of today. One important area of DNA research is that used for genetic and medical research. Our abi...
TAE buffer (Tris-acetate-EDTA) 50X is use in this experiment of nucleic acids’ electrophoresis whether in agarose or polyacrylamide gels (Bisen, 2014). Usually for resolution of RNA and DNA fragment larger than 1500 bp TAE buffer is preferred, for genomic DNA and for large supercoiled DNA. In addition, TAE buffer contain low buffering capacity. Therefore, during prolonged electrophoresis, replacement (periodic) of the buffer is recommended. Furthermore, TBE buffer and also known as Tris-borate-EDTA 10X commonly used in polyacrylamide gel electrophoresis for the DNA and RNA (Kumar & Garg, 2005). TBE buffer is also used for agarose gels but it is rarely used for preparative gels for recovery of nucleic acids. TBE buffer will act as a strong inhibitor for nucleases. Double stranded linear nucleic a...
The birth of genetic engineering and recombinant DNA began in Stanford University, in the year 1970 (Hein). Biochemistry and medicine researchers were pursuing separate research pathways, yet these pathways converged to form what is now known as biotechnology (Hein). The biochemistry department was, at the time, focusing on an animal virus, and found a method of slicing DNA so cleanly that it would reform and go on to infect other cells. (Hein) The medical department focused on bacteria and developed a microscopic molecular messenger, that could not only carry a foreign “blueprint”, or message, but could also get the bacteria to read and copy the information. (Hein) One concept is needed to understand what happened at Stanford: how a bacterial “factory” turns “on” or “off”. (Hein) When a cell is dividing or producing a protein, it uses promoters (“on switches”) to start the process and terminators (“off switches”) to stop the process. (Hein) To form proteins, promoters and terminators are used to tell where the protein begins and where it ends. (Hein) In 1972 Herbert Boyer, a biochemist, provided Stanford with a bacterial enzyme called Eco R1. (Hein) This enzyme is used by bacteria to defend themselves against bacteriophages, or bacterial viruses. (Hein) The biochemistry department used this enzyme as a “molecular scalpel”, to cut a monkey virus called SV40. (Hein) What the Stanford researchers observed was that, when they did this, the virus reformed at the cleaved site in a circular manner. It later went on to infect other cells as if nothing had happened. (Hein) This proved that EcoR1 could cut the bonding sites on two different DNA strands, which could be combined using the “sticky ends” at the sites. (Hein). The contribution towards genetic engineering from the biochemistry department was the observations of EcoR1’s cleavage of