5-Ethynyl-2′-deoxyuridine (EdU) is a
thymidine
Thymidine (symbol dT or dThd), also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. I ...
analogue which is incorporated into the
DNA of dividing cells. EdU is used to assay DNA synthesis in cell culture and detect cells in embryonic, neonatal and adult animals which have undergone DNA synthesis.
Whilst at high doses it can be cytotoxic, this molecule is now widely used to track proliferating cells in multiple biological systems.
EdU-labelling allows cells to be isolated without denaturing RNA, allowing researchers to determine the transcriptional profile of cells. This approach has been used to assess transcription in neuronal cells and tissues that have recently divided either ''in vitro'' or ''in vivo''.
Detection
EdU is detected with a
fluorescent
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...
azide
In chemistry, azide is a linear, polyatomic anion with the formula and structure . It is the conjugate base of hydrazoic acid . Organic azides are organic compounds with the formula , containing the azide functional group. The dominant applic ...
which forms a covalent bond using
click chemistry
In chemical synthesis, click chemistry is a class of biocompatible small molecule reactions commonly used in bioconjugation, allowing the joining of substrates of choice with specific biomolecules. Click chemistry is not a single specific reaction ...
.
Unlike the commonly used
bromodeoxyuridine
Bromodeoxyuridine (5-bromo-2'-deoxyuridine, BrdU, BUdR, BrdUrd, broxuridine) is a synthetic nucleoside analogue with a chemical structure similar to thymidine. BrdU is commonly used to study cell proliferation in living tissues and has been stud ...
, EdU detection requires no heat or acid treatment. EdU incorporated into DNA induces
DNA damage
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA da ...
, primarily during
DNA replication
In molecular biology, DNA replication is the biological process of producing two identical replicas of DNA from one original DNA molecule. DNA replication occurs in all living organisms acting as the most essential part for biological inheritanc ...
, which is reflected by phosphorylation of histone
H2AX
H2A histone family member X (usually abbreviated as H2AX) is a type of histone protein from the H2A family encoded by the ''H2AFX'' gene. An important phosphorylated form is γH2AX (S139), which forms when double-strand breaks appear.
In humans ...
, arrest in the
cell cycle
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subs ...
progression and
apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...
.
References
External links
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{{DEFAULTSORT:Ethynyl-2'-Deoxyuridine, 5-
Nucleosides
Staining dyes
Pyrimidinediones
Ethynyl compounds