7-Aminoactinomycin D

Applications

With an absorption maximum at 546 nm, 7-AAD is efficiently excited using a 543 nm helium–neon laser; it can also be excited with somewhat lower efficiency using a 488 nm or 514 nm argon laser lines. Its emission has a very large Stokes shift with a maximum in the deep red: 647 nm. 7-AAD is therefore compatible with most blue and green fluorophores – and even many red fluorophores – in multicolour applications.

7-AAD does not readily pass through intact cell membranes; if it is to be used as a stain for imaging DNA fluorescence, the cell membrane must be permeabilized or disrupted. This method can be used in combination with formaldehyde fixation of samples.

7-AAD is also used as a cell viability stain. Cells with compromised membranes will stain with 7-AAD, while live cells with intact cell membranes will remain dark. Viability of the cells in flow cytometry should be around 95% but not less than 90%.

Actinomycin D

Main article: Actinomycin

The related compound actinomycin D is nonfluorescent, but binds DNA in the same way as 7-AAD. Its absorbance changes when bound to DNA, and it can be used as a stain in conventional transmission microscopy.

References

Gallery

File:7-AADSpektrum.png|Absorptions

References

1. [http://www.interchim.fr/ft/1/132303.pdf 7-Aminoactinomycin D] at [[Interchim]]
2. Liu X. (1991). "Solution structure of actinomycin-DNA complexes: drug intercalation at isolated G-C sites". J Biomol NMR.
3. Latt S. (1977). "Fluorescent probes of chromosome structure and replication". Can J Genet Cytol.
4. "Flow cytometry (FACS) staining protocol (Cell surface staining)".