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Radioactive materials used in genetic engineering and in other professions help with the identification, diagnosis, research and treatment of diseases. There are two types of radioactive materials used in genetic engineering: radioactive nucleotides and radioactive isotopes.
Radioactive nucleotides and radioactive isotopes are used in combination in the process of labeling cloned DNA. The procedure for labeling DNA probes was developed in 1983. The radioactive nucleotides were then introduced to DNA molecules. The method supplies DNA polymerase with a single-stranded DNA template, a primer, and the four nucleotides. The four nucleotides are kept in a buffered solution, which induces in-vitro replication. The daughter strand, the strand that becomes the probe, is labeled by including a nucleotide in the reaction mix which is linked to a radioactive isotope. The radioactive nucleotide is usually deoxycytosine triphosphate (dCTP), or dATP.
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What is a Radioactive Nucleotide?
A radioactive nucleotide in genetic engineering is used to determine the rate of DNA synthesis, the rapid, efficient, and accurate duplication of the cellular genome.
Nucleotides are chemical units which are strung together within a DNA strand. The radioactive nucleotides are so small that they remain unseen, even with the most powerful microscope. These nucleotides consists of a nitrogenous base attached to a sugar molecule and a phosphate group. There are four different nitrogenous base varieties (designated by letters): A, C, G, and T. These varieties represent adenine, cytosine, guanine, and thymine. The strongest part of each strand is formed by chemical bonds which link the sugar residues of the nucleotides with the phosphate groups, while the bases protrude sideways.
Radioactive nucleotides have shown to be very helpful, and they pose no harm.
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What is a Radioactive Isotope?
Radioactive isotopes (radioisotopes) are artificially created when the unstable nucleus of a chemical element decays. The nucleus emits alpha, beta, or gamma rays until it reaches stability.
Radioisotopes are used in radioactive labeling techniques. These techniques are still being used extensively in gene manipulation experiments but have be proven to cause some problems. The safety of radioactive isotopes is questionable, and they are potentially hazardous. The operator using radioactive isotopes during an experiment may be in danger and should be knowledgeable of the materials being handled.
Experimenters must know how to properly use radioactive isotopes and the proper technique for disposal. Little knowledge of either technique can be dangerous for both the scientist and the environment.
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Safer Techniques for the Future
Scientists are researching safer techniques for genetic engineering in the future using non-radioactive materials. Similiarly, fluorescent labels are being used in DNA labeling.
Safer techniques for genetics engineering experimentation would greatly benefit both the reseracher and the environment.
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Nuclear Medicine Radiochemistry Soceity: Medical Uses of Radioactive Materials - http://www.radiochemistry.org/nuclearmedicine/diagnostics/01_diagnostics.shtml
World Nuclear Medicine: Radioisotopes in Medicine - http://www.world-nuclear.org/info/inf55.html