The Southern Blot Assay in Plants

Southern blotting is a classical molecular biology assay for the detection of a specific DNA sequence from a mixture of DNA fragments. As a very popular biochemical technique for DNA characterization, Southern blotting assay allows direct visualization and evaluation of the identity, size and abundance of DNAs of interest.

The Southern blotting technique was named after Edward M. Southern, who developed this assay in 1975 (1). The basic principle of this assay is to detect known DNA fragments via probe hybridization. In general, large-sized DNA strands (such as genomic DNA) is firstly cut by restriction endonucleases into smaller fragments, which are subjected to gel electrophoresis for size-dependent separation. The DNA fragments on the gel are then transferred to a nylon membrane (the “blotting” step), followed by incubation with DNA probes. Finally, the specific target DNA fragments can be visualized at the membrane by probe hybridization.

With years of experience and expertise on the Southern blotting technique, Lifeasible offers a full array of services that cover every step of the assay, including (2):

1. DNA extraction and preparation
2. DNA cleavage with restriction endonucleases
3. Gel electrophoresis
4. DNA denaturation
5. Blotting
6. Exposure to DNA probes
7. Detection of the DNA of interest

Besides commercially available probes, Lifeasible also provide customized probes to meet the specific needs of each project. Our experienced scientist and experts offer services for the design and synthesis of radioactive probes, fluorescent probes, as well as chemiluminescent probes.

In plant sciences, Southern blotting is regarded as the most reliable method for the identification of transgenic plants. It is commonly used for confirmation of transgene integration and reveal of copy numbers (3, 4). Experienced in plant DNA extraction and handling, scientist and collaborators of Lifeasible have contributed great effort in optimizing the protocol for Southern blotting specialized for the plant system. We proudly provide service with high sensitivity, reliable quality and competitive price. Moreover, our customer-centered service ensures close and efficient communication, guaranteeing that each project is given the attention it needs.