5-ethynyl-2'-deoxyuridine

5-Ethynyl-2'-deoxyuridine (also known as EdU) is a halogenated nucleoside analog of thymidine, a type of nucleoside that is an essential component of DNA. EdU is incorporated into DNA during DNA replication and can be used to label proliferating cells.

Chemistry

5-Ethynyl-2'-deoxyuridine is a synthetic nucleoside analog, meaning it is structurally similar to naturally occurring nucleosides but has been chemically modified. The molecule consists of a deoxyribose sugar, to which a pyrimidine base (specifically, uracil) is attached. The 5-position of the uracil base is substituted with an ethynyl group.

Use in Cell Biology

In cell biology, EdU is used as a marker for DNA synthesis, allowing scientists to identify cells that are in the S phase of the cell cycle. This is because during DNA replication, the EdU is incorporated into the newly synthesized DNA strand in place of thymidine. The incorporated EdU can then be detected using a technique called click chemistry, which involves a reaction between the ethynyl group of EdU and a fluorescently labeled azide. This allows the visualization of DNA synthesis in cells under a fluorescence microscope.

Safety and Toxicity

Like other nucleoside analogs, EdU can have toxic effects on cells and organisms. This is because it can interfere with the normal process of DNA replication, potentially leading to DNA damage and cell death. Therefore, care must be taken when using EdU in experimental settings to ensure that the concentration and exposure time are not excessively high.

See Also

• BrdU
• Click chemistry
• DNA replication
• Cell cycle