7-Amino-actinomycin D

You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.

7-Amino-actinomycin D (also 7-aminoactinomycin D, abbreviated 7-AAD) is a fluorescent chemical compound with a strong affinity for DNA. It is used as a fluorescent marker for DNA in fluorescence microscopy and flow cytometry. It intercalates in double-stranded DNA, with a high affinity for GC-rich regions.

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 th 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 fluorophones – 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. 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.

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.

External links

• Structure from Invitrogen
• MSDS