Ethidium homodimer assay
Encyclopedia
An ethidium homodimer assay can be used to detect dead or dying cells. Ethidium homodimer is a membrane-impermeable fluorescent dye which binds to DNA
. After a cell sample has been stained with ethidium homodimer, the dead cells may be viewed and counted under a UV-light microscope.
When cells die, the plasma membranes of those cells becomes disrupted. Because of this, ethidium homodimer may enter those cells and bind to DNA within those cells. Because live cells don't have a compromised membrane, the ethidium homodimer can't enter.
One reason for doing an ethidium homodimer assay instead of using a TUNEL assay
to measure cell death is that ethidium homodimer stains all of the dead or dying cells, while TUNEL only stains cells that have undergone programmed cell death.
DNA
Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...
. After a cell sample has been stained with ethidium homodimer, the dead cells may be viewed and counted under a UV-light microscope.
When cells die, the plasma membranes of those cells becomes disrupted. Because of this, ethidium homodimer may enter those cells and bind to DNA within those cells. Because live cells don't have a compromised membrane, the ethidium homodimer can't enter.
One reason for doing an ethidium homodimer assay instead of using a TUNEL assay
TUNEL assay
Terminal deoxynucleotidyl transferase dUTP nick end labeling is a method for detecting DNA fragmentation by labeling the terminal end of nucleic acids.- Method :...
to measure cell death is that ethidium homodimer stains all of the dead or dying cells, while TUNEL only stains cells that have undergone programmed cell death.