What is a tag or probe?

A tag or probe is a molecular tool used in various biological and chemical assays to detect or quantify specific substances, such as proteins, nucleic acids, or small molecules. Tags are often attached to antibodies, nucleotides, or other biomolecules, enabling visualization or measurement through techniques like fluorescence, radioactivity, or enzymatic activity. Probes can be either specific sequences of nucleotides that bind to complementary DNA or RNA or small molecules that bind to target proteins. Overall, tags and probes are essential for studying biological interactions and processes.