AAT Bioquest

Why are Annexin V conjugates and 7-AAD used together?

Posted November 7, 2022


Using Annexin V conjugates and 7-AAD (7-amino-actinomycin D) together is the most effective way to differentiate early apoptosis from late apoptosis and necrosis.  

Annexin V conjugates are an efficient label for staining phosphatidylserines (PS), which are expressed on the outer layer of the plasma membrane by early apoptotic cells. 

On the other hand, 7-AAD is a membrane-impermeant fluorescent dye that is unable to reach the DNA in viable cells. It is only capable of binding to DNA in late apoptotic cells and necrotic cells that have lost their membrane integrity. 

Hence, using both labels together allows scientists to distinguish early apoptosis from late apoptosis and necrosis. 

Additional resources

Modified Annexin V/Propidium Iodide Apoptosis Assay For Accurate Assessment of Cell Death

Annexin-V Staining

Cell Viability Assays

Annexin V, FITC Labeled

7-AAD [7-Aminoactinomycin D] *CAS 7240-37-1*