Radioactive

(adjective)

A particle that has spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.

Related Terms

Examples of Radioactive in the following topics:

  • Stable Isotopes

    • Stable isotopes are atoms that are not radioactive, in other words, they are not going to lose neutrons and decay spontaneously.
    • Adding or subtracting neutrons from an atom does not change the elemental properties, but it can alter some of its features (like making it more radioactive).
    • A stable isotope is a chemical isotope that is not radioactive.

  • Radiation

    • X-ray sterilization is an electricity based process that does not require chemical or radioactive material.
    • Irradiation with X-rays or gamma rays does not make materials radioactive.
    • Irradiation with particles may make materials radioactive, depending on the type of particles, their energy, and the type of target material: neutrons and very high-energy particles can make materials radioactive but have good penetration, whereas lower energy particles (other than neutrons) cannot make materials radioactive, but have poorer penetration.

  • DNA Protection Analysis

    • The method uses an enzyme, deoxyribonuclease (DNase, for short) to cut the radioactively end-labeled DNA, followed by gel electrophoresis to detect the resulting cleavage pattern.
    • For example, the DNA fragment of interest may be amplified by polymerase chain reaction, with the result being many DNA molecules with a radioactive label on one end of one strand of each double stranded molecule.

  • DNA Sequencing Based on Sanger Dideoxynucleotides

    • The ddNTPs may be radioactively or fluorescently labelled for detection in automated sequencing machines.The DNA sample is divided into four separate sequencing reactions, containing all four of the standard deoxynucleotides (dATP, dGTP, dCTP and dTTP) and the DNA polymerase.
    • Technical variations of chain-termination sequencing include tagging with nucleotides containing radioactive phosphorus for radiolabelling, or using a primer labeled at the 5' end with a fluorescent dye.

  • Chemical Assays, Radioisotopic Methods, and Microelectrodes

    • Radioisotopes are specific types of isotopes that emit radioactivity.

  • Common Bacterial Traits

    • Bacteria grow in soil, acidic hot springs, radioactive waste, water, and deep in the Earth's crust.

  • Immunotherapy for Cancer

    • Radioimmunotherapy in turn involves the use of radioactively conjugated murine antibodies against cellular antigens, mostly for treatment of lymphomas.

  • Sodium Pumps as an Alternative to Proton Pumps

    • This was investigated by following the passage of radioactively labeled ions across the plasma membrane of certain cells.