Streptavidin
Streptavidin is a protein that is derived from the bacterium Streptomyces avidinii. It has a high affinity for the biotin, which makes it a valuable tool in molecular biology and biotechnology. Streptavidin is commonly used as a molecular tag to label and detect specific molecules in various assays. It is often conjugated with fluorescent dyes, enzymes, or other molecules that can be easily detected. This allows researchers to visualize and quantify the presence of specific molecules in a sample.