It is used in treatment of blood cancer and bone diseases
Phosphorus-32 is a radioactive isotope of phosphorus. The nucleus of phosphorus-32 contains 15 protons and 17 neutrons, one more neutron than the most common isotope of phosphorus, phosphorus-31. Phosphorus-32 only exists in small quantities on Earth as it has a short half-life of 14.29 days and so decays rapidly.
Phosphorus is found in many organic molecules and so phosphorus-32 has many applications in medicine, biochemistry and molecular biology where it can be used to trace phosphorylated molecules, e.g. in elucidating metabolic pathways, and radioactively label DNA.
Phosphorus is abundant in biological systems and, as a radioactive isotope is almost chemically identical with stable isotopes of the same element, phosphorus-32 can be used to label biological molecules. The beta radiation emitted by the phosphorus-32 is sufficiently penetrating to be detected outside the organism or tissue which is being analysed
Nuclear medicine
Many radioisotopes are used as tracers in nuclear medicine, including iodine-131, phosphorus-32, and technetium-99m. Phosphorus-32 is of particular use in the identification of malignant tumours because cancerous cells have a tendency to accumulate more phosphate than normal cells.[4] The location of the phosphorus-32 can be traced from outside the body to identify the location of potentially malignant tumors.
The radiation emitted by phosphorus-32 can be used for therapeutic as well as diagnostic purposes. The use of 32P-chromic phosphate has been explored as a possible chemotherapy agent to treat disseminated ovarian cancer.[5] In this situation it is the longterm toxic effects of beta radiation from phosphorus-32 accumulating in the cancerous cells which has the therapeutic effect.The Phosphorus-32 is widely used radioisotope for cancer detection and treatment, especially in eyes and skin cancer.
Biochemistry and molecular biology
The metabolic pathways of organisms extensively use phosphorus in the generation of different biomolecules within the cell. Phosphorus-32 finds use for analysing metabolic pathways in pulse chase experiments where a culture of cells is treated for a short time with a phosphorus-32-containing substrate. The sequence of chemical changes which happen to the substrate can then be traced by detecting which molecules contain the phosphorus-32 at multiple time points following the initial treatment.
DNA contains a large quantity of phosphorus in the phosphodiester linkages between bases in the oligonucleotide chain. DNA can therefore be tracked by replacing the phosphorus with phosphorus-32. This technique is extensively used in Southern blot analysis of DNA samples. In this case a phosphorus-32-containing DNA probe hybridises to its complementary sequence where it appears in a gel. Its location can then be detected by photographic film.
Plant sciences
Phosphorus-32 is used in plant sciences for tracking a plant's uptake of fertiliser from the roots to the leaves. The phosphorus-32-labelled fertiliser is given to the plant hydroponically or via water in the soil and the usage of the phosphorus can be mapped from the emitted beta radiation. The information gathered by mapping the fertiliser uptake show how the plant takes up and uses the phosphorus from fertiliser.