What does the "Southern Blot" technique primarily analyze?

The Southern Blot technique is primarily used to analyze DNA. Developed by Edwin Southern, this method allows for the detection of specific DNA sequences within a complex mixture of DNA. It involves the processes of gel electrophoresis to separate DNA fragments by size, followed by transfer of these fragments onto a membrane, and then probing with a labeled DNA probe that is complementary to the target sequence. This enables researchers to identify the presence or absence of specific genes or genetic elements in a sample.

The technique is pivotal for various applications in molecular biology, including gene cloning, detection of mutations, and genetic fingerprinting. Its specificity for DNA makes it a fundamental tool in genetic mapping and diagnostics. Other techniques exist that analyze RNA and proteins—such as Northern Blot for RNA and Western Blot for proteins—but Southern Blot is specifically designed for DNA analysis. Carbohydrates are not analyzed using this technique, as they typically require other forms of biochemical analysis.