Final answer:
Southern blotting uses radioactive or fluorescent probes to detect specific DNA sequences in a DNA sample. The process includes gel electrophoresis, transfer of DNA to a membrane, and probe hybridization, followed by visualization through autoradiography or fluorescence.
Step-by-step explanation:
Southern blotting is a molecular biology technique that utilizes radioactive or fluorescent probes to detect the presence of specific DNA sequences within a DNA sample. This technique involves separating DNA fragments by agarose gel electrophoresis, transferring them to a nylon or nitrocellulose membrane, and then incubating the membrane with a single-stranded DNA probe that is labeled with a radioactive phosphorus atom or a fluorescent dye.
The probe is designed to be complementary to the DNA sequence of interest, allowing it to hybridize with the target sequence on the membrane. The hybridization is then visualized through autoradiography or fluorescence, depending on the type of label used on the probe. Southern blotting is a critical tool for researchers to analyze genetic information and has applications in gene identification, profiling of alterations in the genome, and the study of gene expression patterns.