[Histonet] Re: Peroxidase block again....

[Johnson, Teri]

Gene,

Why would you want to eliminate peroxidase blocking as part of your immunostaining procedure? It's cheap, it's quick, it's easy, and if you think it interferes with the ability of the primary antibody to bind with the antigen, you add it as a step after application of the primary antibody. Simply use aqueous hydrogen peroxide instead of methanolic routinely, and you won't have to worry about the potential of methanol to interfere with the immunoreactivity of the tissues for CD markers.

You absolutely can leave it out and learn to ignore the positive staining of the RBCs and other tissues, and control what's labeled endogenous staining by including a negative control. Frankly, unless there is a scientific reason to have it included (i.e. looking for antigen positivity (demonstrated by a different enzyme) in cells/tissues which contain endogenous peroxidase), it's best to get rid of it.

Teri Johnson, HT(ASCP)QIHC
Managing Director Histology Facility
Stowers Institute for Medical Research
1000 E. 50th St.
Kansas City, MO 64110