Which radioactive label is commonly used in hybridization techniques?

The use of radioactive labels in hybridization techniques provides a highly sensitive way to detect nucleic acids. Phosphorus-32 (P32) is a radioactive isotope that emits beta radiation, making it useful for various molecular biology applications, such as tracking and quantifying DNA or RNA during hybridization experiments.

P32 can be incorporated into nucleic acid probes, allowing these probes to bind to their complementary sequences in a sample. When the labeled probes hybridize to the DNA or RNA of interest, the emitted radiation can then be measured, which indicates the presence and quantity of the target nucleic acids. This method is particularly effective due to the high sensitivity of detection that radioactive labels offer, enabling researchers to identify even low-abundance targets.

Other labels mentioned, like biotin or fluorescein, are non-radioactive and rely on other detection methods, such as enzyme-linked assays or fluorescence imaging, which, while useful, do not provide the same level of sensitivity that radioactive isotopes like P32 offer in specific applications.