DNA probes are short, single-stranded sequences of DNA that are designed to bind to specific complementary sequences in a sample. They are used in various applications, including genetic testing, diagnostic medicine, and forensic analysis, to identify the presence of particular genes or mutations. When a DNA probe binds to its target sequence, it can be detected using various methods, such as fluorescence or radioactivity. This allows scientists to visualize and analyze specific DNA segments, making probes essential tools in molecular biology and genetics research.