Hello!
I am hoping to get some feedback on what everyone currently uses to label cytolytic T lymphocytes in mouse tissue.

One question I have is: What is the difference between CD8a and CD8b? I realize CD8a corresponds with the alpha chain, and CD8b beta chain, but will/should they both hit ALL CD8 positive cells?

And more importantly, I have heard that some dendritic cells express the CD8 alpha chain. Has anyone seen evidence of CD8a picking up not only CTL's but some dendritics as well?
The reason why I ask is the anti-mouse CD8a we currently use I just found out--is reportedly listed to react with CTL's-- as well as a subset of dendritic cells (!), and CD8b is listed as CTL exclusive. When we compared CD8a side by side with CD8b, we did see less positive cell staining with CD8b. But I have also been told that CD8b may not pick up all CD8 positive cells. 

So I need an antibody that targets ALL CD8 positive cells in mouse tissue, and won't pick up dendritics or anything else! Any comments or suggestions? Any feedback will be greatly appreciated! 

Thanks
Melissa