You can label bacteria with many radioisotopes. The most commonly used are H3, C14, S35 or P32 and those all have a half life longer than 10 days. Either the isotope can be added to the medium or more commonly added as a precursor such as a radiolabelled amino acid or nucleotide for example.

thank you so much sir for your assist. one more think that i want to ask from you....is C14 or other one isotopes used for any type of species of bacteria.

If yes then suggest me the reference.

All species should label well with all of the isotopes since each labels essential components of life. C14 will label all organic molecules (which is nearly everything), P32 will label nucleic acids such as the DNA, S35 will predominantly label proteins. This of course assumes the bacteria are actually growing and therefore able to incorporate the radioisotopes during growth.

Thank you so much for your kind information.

Dear Dr.

Article Radiolabeled Microorganisms: Comparison of Different Radiois...

Dear Ashwani,

Iodine-131 and phosphorus-32 are also commonly used in radiotherapy. More radical uses of radioisotopes include the use of Boron-10 to specifically attack tumor cells. Boron-10 concentrates in tumor cells and is then subjected to neutron beams that result in highly energetic alpha particles that are lethal to the tumor tissue. More modern methods of irradiation include the production of x rays from linear accelerators. Because they can be detected in low doses, radioisotopes can also be used in sophisticated and delicate biochemical assays or analysis.

For microbiology and immunology applications

Radiolabeling has allowed for great advances in microbiological research. Radioactive hydrogen, sulphur and phosphorus are popularly common.

(1) for DNA analysis

Various radioactive compounds are used in microbiological analyses to label different constituents of the bacterial cell. Radioactive hydrogen (i.e., tritium) can be used to produce radioactive deoxyribonucleic acid. The radioactive DNA can be detected by storing the DNA sample in contact with X-ray film. The radioactive particles that are emitted from the sample will expose the film. When the film is developed, the result is an image of the DNA. This process, which is known as autoradiography, has long been used to trace the elongation of DNA, and so determine the speed at which the DNA is replicating.

(2) DNA can also be labeled, but in a different location within the molecule, by the use of radioactive phosphorus.

(3) Bacterial viruses were exposed to either radioactive sulfur or phosphorus. The sulfur radiolabeled the surface of the virus, while the phosphorus labeled the DNA. Viruses allowed to infect bacteria and then mechanically sheared off of the bacteria. The sheared viruses were then collected separately from the bacteria. Radioactive sulfur can be found useful in the virus suspension and radioactive phosphorus in the bacteria.

Note ***35S radioisotope is not suitable for DNA labelling based studies because DNA does not contain sulfur.

Ashish