How do I interpret the results of southern blot?

The results of Southern blot are visualized as bands on the membrane. These bands represent DNA fragments of various sizes. To determine the size of these fragments, their relative lengths are compared to those of DNA bands with known sizes. When a probe hybridizes with specific DNA on the membrane, it indicates that the probe possesses a complementary sequence to that DNA fragment. If the probe hybridizes with a single undigested DNA fragment, only one band will appear on the final blot. However, if the probe binds to multiple similar sequences, multiple bands will be observed.