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Application of Radioisotopes in Biology

Radioactive isotopes have a variety of applications as they are useful as the radioactivity of these isotopes can be detected or the energy released by them can be used.  Radioisotopes are effective traces as their radioactivity is easy to detect. Tracers can be used to detect leaks in underground water pipes; also they can be used to follow steps of a complex chemical reaction.

A good example of uses of radioisotopes in biology is using the carbon-14 isotopes in determining the steps in the process of photosynthesis in plants. Other use of radioisotope is for establishing age of various objects.

Radiations that are emitted by some radioactive substances can be used to kill microorganisms in foodstuffs which enable to prolong the shelf life of these products. Agricultural produce like tomatoes sprouts, mushrooms and berries are irradiated with emissions from radioisotopes like cobalt-60 or cesium-137. The process of irradiation kills a lot of bacteria that can cause spoilage of food. Radioactive isotopes are used in various medical applications. They are used in diagnosing and treating illness and diseases.

Radioisotopes in biology have numerous applications. Radioisotopes have extensive application in molecular biology. Radioisotopes can be incorporated into DNA, RNA and protein molecules both in vivo and in vitro conditions. The molecules of interest or the metabolic pathway can be traced or investigated.

Applications of Radioisotopes in Biology
Isotopes in biology are used in the following manner: 
  • Used in Urea breath test, it performed to detect the presence of Helicobacter pylori in the stomach. The isotope used here is carbon-14, and is also used in determination of hormone concentration in the plasma and in radioimmunoassay techniques.
  • Calcium-47 isotopes are important to biomedical research. It aids in studying the cellular functions of formation of bone sin mammals.
  • Carbon-14 is a major research tool. It helps to the testing the potentiality of new drugs whether it is metabolized without formation of harmful byproducts. It is also used in biological research, pollution control, agriculture and archeology.
  • Cesium-137 is a radioisotope used in the treatment of cancerous tumors. Also it is used to measure the correct dosages of radioactive pharmaceuticals given to patients. It also used to maintain the right level for food, drugs packaging.
  • Chromium-51 is used in the studies of red blood cell survival.
  • Cobalt-57 is used a tracer; it is used to diagnose pernicious anemia.
  • Cobalt-60 is used in sterilization of surgical instruments. It is also used in treatment of cancer, irradiation of food products.
  • Copper-67 helps to destroy the cancer tumor when it is injected with monoclonal antibodies.
  • Gallium-67 is used in medical diagnosis.
  • Idonie-123 is widely used in the diagnosis of thyroid disorder and diagnosis of disorders of metabolism including functions of brain.
  • Iodine-129 is used in in-vitro diagnostic laboratories.
  • Iodine-131 isotope is used in treatment of thyroid disorders like Grave's disease.
  • An isotope of iron - iron-55 is used in metabolism research.
  • Phosphorus-32 is used in the research concerning molecular biology and genetics.
  • Selenium-75 is used in studies of proteins in life sciences research.
  • Strontium-85 is used in the study of formation of bone and metabolism.
  • Sulphur-35 is used in the studies of genetics and molecular biology.
  • Technetium-99m is used in blood flow studies and also different chemical forms of this isotope are used for kidney, liver, spleen, bone and brain imaging.
  • Xenon-133 is used in nuclear medicinal studies for lung ventilation and blood flow studies.

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From Wikipedia


A radionuclide is an atom with an unstable nucleus, which is a nucleus characterized by excess energy which is available to be imparted either to a newly-created radiation particle within the nucleus, or else to an atomic electron. The radionuclide, in this process, undergoes radioactive decay, and emits a gamma ray(s) and/or subatomic particles. These particles constitute ionizing radiation. Radionuclides may occur naturally, but can also be artificially produced.

The number of radionuclides is uncertain because the number of very short-lived radionuclides that have yet to be characterized is extremely large and potentially unquantifiable. Even the number of long-lived radionuclides is uncertain (to a smaller degree), because many "stable" nuclides are calculated to have half lives so long that their decay has not been experimentally measured. The nuclide list contain 90 nuclides that are theoretically stable, and 255 total stable nuclides that have not been observed to decay. In addition, there exist about 650 radionuclides that have been experimentally observed to decay, with half lives longer than 60 minutes (see list of nuclides for this list). Of these, about 339 are known from nature (they have been observed on Earth, and not as a consequence of man-made activities).

Including artificially produced nuclides, more than 3300 nuclides are known (including ~3000 radionuclides), including many more (> ~2400) that have decay half lives shorter than 60 minutes. This list expands as new radionuclides with very short half lives are characterized.

Radionuclides are often referred to by chemists and physicists, as radioactive isotopes or radioisotopes. Radioisotopes with suitable half lives play an important part in a number of constructive technologies (for example, nuclear medicine). However, radionuclides can also present both real and perceived dangers to health.


Naturally occurring radionuclides fall into three categories: primordial radionuclides, secondary radionuclides and cosmogenic radionuclides. Primordial radionuclides originate mainly from the interiors of stars and, like uranium and thorium, are still present because their half-lives are so long that they have not yet completely decayed. Secondary radionuclides are radiogenic isotopes derived from the decay of primordial radionuclides. They have shorter half-lives than primordial radionuclides. Cosmogenic isotopes, such as carbon-14, are present because they are continually being formed in the atmosphere due to cosmic rays.

Artificially produced radionuclides can be produced by nuclear reactors, particle accelerators or by radionuclide generators:

  • Radioisotopes produced with nuclear reactors exploit the high flux of neutrons present. The neutrons activate elements placed within the reactor. A typical product from a nuclear reactor is thallium-201 and iridium-192. The elements that have a large propensity to take up the neutrons in the reactor are said to have a high neutron cross-section.
  • Particle accelerators such as cyclotrons accelerate particles to bombard a target to produce radionuclides. Cyclotrons accelerate protons at a target to produce positron emitting radioisotopes e.g. fluorine-18.
  • Radionuclide generators contain a parent isotope that decays to produce a radioisotope. The parent is usually produced in a nuclear reactor. A typical example is the technetium-99mgenerator used in nuclear medicine. The parent produced in the reactor is molybdenum-99.
  • Radionuclides are produced as an unavoidable side effect of nuclear and thermonuclear explosions.

Trace radionuclides are those that occur in tiny amounts in nature either due to inherent rarity, or to half-lives that are significantly shorter than the age of the Earth. Synthetic isotopes are inherently not naturally occurring on Earth, but can be created by nuclear reactions.


Radionuclides are used in two major ways: for their chemical properties and as sources of radiation. Radionuclides of familiar elements such as carbon can serve as tracers because they are chemically very similar to the non-radioactive nuclides, so most chemical, biological, and ecological processes treat them in a near identical way. One can then examine the result with a radiation detector, such as a geiger counter, to determine where the provided atoms ended up. For example, one might culture plants in an environment in which the carbon dioxide contained radioactive carbon; then the parts of the plant that had laid down atmospheric carbon would be radioactive.

In nuclear medicine, radioisotopes are used for diagnosis, treatment, and research. Radioactive chemical tracers emitting gamma rays or positrons can provide diagnostic information about a person's internal anatomy and the functioning of specific organs. This is used in some forms of tomography: single photon emission computed tomography and positron emission tomography scanning.

From Encyclopedia

Biology: Mendelian Genetics BIOLOGY: MENDELIAN GENETICS

Gregor Mendel was an Austrian monk who, as a result of experimentation in plant hybridization between 1856 and 1863, discovered that certain parental characteristics are dominant in the next generation and others are what he called recessive (that is, they do not appear but can be passed on to the next generation). Moreover, he found that such parental traits segregate themselves in a precise numerical ratio. Thus, if A represents a dominant round seed shape and a a recessive angular shape, then one-quarter of the progeny will have the dominant (AA), one-quarter the recessive (aa), and one-half will have a dominant and a recessive (Aa or aA), what is now called a heterozygous combi-nation. Mendel's work was scarcely noted at the time. It was not until 1900 that three European biologists, Hugo de Vries, Karl Correns, and Erich von Tschermak independently rediscovered Mendel's "principle of segregation." In 1909 the Danish biologist Wilhelm Johannsen coined the terms that became standard: gene to represent the unit of heredity, genotype to designate the genetic makeup of an organism, and phenotype to denote the actual appearance of the organism. The horticultural methods of plant breeder Luther Burbank, famous for his spectacular new varieties of fruit, attracted the interest of professional biologists. In 1905 the Carnegie Institution, a foundation interested in backing useful scientific projects, looked into Burbank's methods and results. The institution's president, Robert S. Wood-ward, went so far as to visit Burbank's farm. Bur-bank, Woodward reported to his board, "is like a mathematician who never has to refer to his formulas; all information he possesses he can summon in an instant for his use.… He is not a trained man of science; he lacks knowledge of the terminology of modern science. He often expresses himself in a way quite offensive to many scientific men, if due allowance is not made; but he is a man who unconsciously works by the scientific method to the most extraordinary advantage. I think anybody who goes to his orchards and sees what he has produced and who studies Mr. Bur-bank as I have done will admit at once that he is a most unusual man." Woodward thought Burbank's work was valuable for all humanity. Andrew Carnegie himself agreed but urged that scientists be kept away from him. The following year, the institution sent the pioneer geneticist George H. Shull to interview Bur-bank. Shull found that Burbank's notions of science were largely preconceptions. In particular, Burbank held on to ideas that contemporary genetic science had discredited, such as the notion that alterations in the environment directly cause genetic change through the inheritance of acquired characteristics : "He holds that nothing but acquired characters may be inherited and is thus led to attribute every variation to environmental causes in a more definite way than observations would warrant. Again, without knowing just what the various scientists and philosophers have learned or taught, he takes sides strongly,— against Weismann, Mendel, and De Vries, and with Darwin, and the modern opponents of mutation and Mendelism." The scientists' bottom line on Burbank was that he was a pragmatic plant breeder with scant capacity for understanding what he had really done. Nathan and Ida H. Reingold, Science in America: A Documentary History (Chicago: University of Chicago Press, 1981). American curiosity about genetics was first evinced by farmers interested in breeding. With the foundation of agricultural experimental stations and the establishment of agricultural colleges in the decades after the Civil War, agricultural scientists were naturally interested in the improvement of varieties of plants and animals through hybridization (or crossing, as it was then called) and selection ("breeding from the best"). In 1899 some American professors, including Liberty Hyde Bailey of Cornell University's agricultural college, attended the first International Conference on Hybridization in London. Then in 1903 Bailey and others with similar interests founded the American Breeders' Association to promote the scientific approach to breeding. From the beginning, members of the association were interested both in Mendel's laws and in de Vries's theory of mutation, which stressed the importance of sharp, discontinuous changes in heredity. Between 1903 and 1909 as many as one-fifth of the papers presented at the annual meeting of the association discussed Mendel's ideas, and at the 1907 meeting George H. Shull gave a paper praising de Vries's theory and stressing its significance to breeders. The reason for the strong, early interest in Mendel is clear: his laws made it possible to predict the probable outcomes of specific breeding strategies. In 1910 the association began publication of the American Breeders' Magazine, the first American journal devoted to genetics. In 1912 the association was reorganized as the American Genetic Association, and the journal became the Journal of Heredity. The new attention given to Mendel's work stimulated microscopic research into the structure and function of chromosomes. In 1902 two graduate students at Columbia University, zoologist Walter Sutton and botanist W. A. Cannon, first suggested that the division of chromosomes might be the mechanism that explained Mendelian segregation. Around the same time, Clarence E. McClung, then at the University of Kansas, discovered the role of the X chromosome in the determination of sex. It had been understood by scientists for some years that chromosomes appeared to be paired. McClung argued that gender is the only hereditary characteristic that divides organisms into two equal groups. McClung thought the X chromosome, which was unpaired, was an "accessory" chromosome that determined gender (he thought wrongly that the presence of the X chromosome in a sperm would produce a male offspring; in fact it denotes a female). In 1905 E. B. Wilson at Columbia and Nettie Stevens at Bryn Mawr, working independently, demonstrated that all eggs have a single X chromosome, while a sperm may carry an X or a Y; female animals generally have two X chromosomes, males one X and one Y. The common fruit fly, Drosophila melanogaster, has proven to be the classic organism used for genetic experimentation because its reproductive cycle is short (ten days to three weeks), it has large numbers of offspring (one hundred to four hundred or more), and it has only a few chromosomes. During the first decade of the twentieth century, it became the laboratory subject of choice for genetic experiments. The first American biologist to use the fruit fly for genetic research was William E. Castle, at Harvard in 1901. Other pioneer experimenters, such as William Moenkhaus at Indiana and Frank Lutz at Cold Spring Harbor (the Carnegie Institution's laboratory of experimental evolution), learned of the fruit fly from Castle. The greatest experimental geneticist of the first half of the twentieth century, Thomas Hunt Morgan, then at Columbia University, heard about the technique from Lutz in 1906 and passed it on to several of his students, including Stevens. In addition to its utility in research, Drosophila also proved to be an ideal teaching instrument: fly colonies were easy to maintain, lent themselves to classroom demonstration, and used little laboratory space. Morgan first saw the relationship of fruit flies to genetic research in 1907, when he began to suspect that it would be easy to induce mutations in them and so test de Vries's theory. The idea was to subject the flies to extremes of temperature, centrifuging, and finally the application of X rays. But Morgan's real interest in this line of research began in 1909 when he thought that fruit flies would be ideal subjects on which to test Charles Darwin's ideas about natural selection. In order to show this, he needed to recreate natural situations in the laboratory, wherein variations, produced by mutation, would occur with the same incidence as they did in nature. By linking de Vries's notion of mutation with Darwin's concept of variation, Morgan invented a line of ex

From Yahoo Answers

Question:advantages and disadvantages of radioisotopes? In (a) Health (b) Agriculture (c) Industries (d) Defense

Answers:Health Nuclear medicine uses radiation to provide diagnostic information about the functioning of a person's specific organs, or to treat them. Diagnostic procedures are now routine. Radiotherapy can be used to treat some medical conditions, especially cancer, using radiation to weaken or destroy particular targeted cells. Tens of millions of nuclear medicine procedures are performed each year, and demand for radioisotopes is increasing rapidly. Industry Modern industry uses radioisotopes in a variety of ways to improve productivity and, in some cases, to gain information that cannot be obtained in any other way. Sealed radioactive sources are used in industrial radiography, gauging applications and mineral analysis. Short-lived radioactive material is used in flow tracing and mixing measurements. Gamma sterilisation is used for medical supplies, some bulk commodities and, increasingly, for food preservation. Nuclear techniques are increasingly used in industry and environmental management. The continuous analysis and rapid response of nuclear techniques, many involving radioisotopes, mean that reliable flow and analytic data can be constantly available. This results in reduced costs with increased product quality.

Question:Can people help me as i have to find out about applications of radioisotopes in industry or medical etc, Thanks

Answers:Did u mean natural or artificial Radioactivity..??? Well here are for artificial radioactivity............ there are many uses: - 1. IN MEDICINE FOR DIAGNOSTICS AS A TRACER: - a tracer is a minute amount of radio isotope which is mixed with a nonradioactive medium and injected into the vein of the patient.A radiation detecting device like a Geiger Mullar counter is used to locate blood clots or blocks by moving the counter slowly to different parts of the body. For this purpose radio Na at.no. 11 at.mass 24 is used. IODINE atomic no. 53 atomic mass 131(radio iodine) is used as a tracer to determine the activity of the thyroid gland. radio Na is also used to check the functioning of the heart and maintaining blood circulation. FOR RADIOTHERAPY: - Radio Iodine is also used in the treatment of defects in the Thyroid gland. Radio Cobalt at.no.27 at.mass 60 is used in the treatment of cancer in place of more expensive Radium. Radio phosphorous at. no.15 at.mass 32 is used in the study of bone metabolism & for the treatement of blood diseases. 2. IN INDUSTRY: - Radio isotopes are used a. in testing and controlling the thickness of paper, metal and rubber sheets. b. in detecting flaws in the interior of metal castings (radio Na) c. in detecting wear and tear of machinery d.in detecting welding defects in pipe lines. 3. IN AGRICULTURE a. Radio phosphorus is used in fertilisers to study the assimilation of phosphorus by plants, thus leading to the improvement of fertilizers b. Radiation from radio isotopes are used for developing high variety of rice and wheat 4. IN ANTHROPOLOGY Radio Carbon at.no.6 at.mass14 is used in estimating the age of the earth, relics, mummies, fossils etc... PS : - Radio carbon is also used in the study of protein metabolism and archeological dating. HOPE THIS HELPS YOU.............

Question:- Is genetic algorithm math? - What types are there?

Answers:Not necessarily related to biological sciences per se. The name originates from adopting the evolutionary model for solution finding. "A genetic algorithm (GA) is a search technique used in computing to find exact or approximate solutions to optimization and search problems. Genetic algorithms are categorized as global search heuristics. Genetic algorithms are a particular class of evolutionary algorithms (also known as evolutionary computation) that use techniques inspired by evolutionary biology such as inheritance, mutation, selection, and crossover (also called recombination)."

Question:I'm in high school and for a chapter, we're learning about chemistry and our teacher makes us look for our answers by not using word-for-word definitions...and I'm confused. 1. Explain the terms. 2. What are they. 3. How do they work. 4. Connect the 2 terms. 5. Give an example.

Answers:Radioisotopes (http://en.wikipedia.org/wiki/Radioisotope) are radioactive materials that can be used as tracers or to deliver a concentrated radioactive dose. Nuclear Medicine is based on the use of radioisotopes to treat or diagnose. An isotope (http://en.wikipedia.org/wiki/Isotopes) is a not normal form of a specific element, radioactive ones are not stable and decay through radiation. The radiation is produced from the atomic particles themselves breaking down over time. This time is measured in half-lives (http://en.wikipedia.org/wiki/Half-lives). A half life is the amount of time it takes for a given isotope to degrade to 50% of its original amount. So if it takes 1 year for 1 ounce of radioactive material to decay to the point where only 1/2 of an ounce is left the material has a half-life of 1 year. Radiation is usually thought of as a stream of neutrons, but it can also be parts of the nucleus (like alpha particles) or electrons (beta particles). The gamma radiation is more energetic and destructive. X-rays are created by a radiation source shot through a person onto a sheet of film positioned underneath or behind them. The FDA just recently allowed irradiated fruit and vegetables to be marketed; they are exposed to lethal doses of radiation to kill germs. Cancer is often treated with radioactive materials injected into the area to kill the cancer before killing the person. Radioactive iodine can be injected and it will concentrate itself in the thyroid. This can be used to treat thyroid cancer or to treat the mechanisms that send iodine to the thyroid. Radioactive Carbon 14 is present in every hydrocarbon compound or carbon based life form and is the basis for radiological dating. A CAT scan is often done with the injection of contrasts or dyes; most are radioactive and provide a clearer image for the x-ray by producing radiation inside of the body. A recent assassination of a former Russian Agent was done through the use of radiologicals; the radiation gave him massive cancer and killed him in a few days. A smoke detector uses a radioactive source and a sensor to check for smoke, when the smoke blocks the radiation the sensor detects less radiation and knows that there is smoke in the air. A nuclear densitometer is used to fire a stream of radiation into the ground to determine how dense it is so you can determine if the ground needs to be compacted before construction can begin. Both systems typically use Americum )http://en.wikipedia.org/wiki/Americium), but not in amounts that would be harmful if you are exposed to it. According to Wikipedia: http://en.wikipedia.org/wiki/Radioisotopes "Radionuclides are used in two major ways: for their chemical properties and as sources of radiation. Radionuclides of familiar elements such as carbon can serve as tracers because they are chemically very similar to the non-radioactive nuclides, so most chemical, biological, and ecological processes treat them in a near identical way. One can then examine the result with a radiation detector, such as a geiger counter, to determine where the provided atoms ended up. For example, one might culture plants in an environment in which the carbon dioxide contained radioactive carbon; then the parts of the plant that had laid down atmospheric carbon would be radioactive. In nuclear medicine, radioisotopes are used for diagnosis, treatment, and research. Radioactive chemical tracers emitting gamma rays or positrons can provide diagnostic information about a person's internal anatomy and the functioning of specific organs. This is used in some forms of tomography: single photon emission computed tomography and positron emission tomography scanning. Some Radioactive Isotopes can be really useful nowadays. Cobalt-60 is used to treat tumors and cancer in hospitals. Uranium-235 is used in powerplants. Radioisotopes are also a promising method of treatment in hemopoietic forms of tumors, while the success for treatment of solid tumors has been limited so far. More powerful gamma sources sterilise syringes and other medical equipment. About one in two people in Western countries are likely to experience the benefits of nuclear medicine in their lifetime. In biochemistry and genetics, radionuclides label molecules and allow tracing chemical and physiological processes occurring in living organisms, such as DNA replication or amino acid transport. In food preservation, radiation is used to stop the sprouting of root crops after harvesting, to kill parasites and pests, and to control the ripening of stored fruit and vegetables. In agriculture and animal husbandry, radionuclides also play an important role. They produce high intake of crops, disease and weather resistant varieties of crops, to study how fertilisers and insecticides work, and to improve the production and health of domestic animals. Industrially, and in mining, radionuclides examine welds, to detect leaks, to study the rate of wear, erosion and corrosion of metals, and for on-stream analysis of a wide range of minerals and fuels. Most household smoke detectors contain the radionuclide americium formed in nuclear reactors, saving many lives. Radionuclides trace and analyze pollutants, to study the movement of surface water, and to measure water runoffs from rain and snow, as well as the flow rates of streams and rivers. Natural radionuclides are used in geology, archaeology, and paleontology to measure ages of rocks, minerals, and fossil materials."

From Youtube

Radioisotope Applications.mpg :A few applications of radioisotopes.

Radioactivity and Radioisotopes Revision Video for A Level Physics :A revision video for the WJEC A-Level Physics module PH5 topic on radioactivity and radioisotopes. This may be applicable to other syllabuses. The song is JLS - Beat Again (Digital Dog Remix).