Katie,
           there have been several approaches to processing lung and
ensuring that the reagents are not excluded by the air in the bronchial
tree.
One approach was to use fixatives with low surface tension such as alcohol
containing fixatives or to add  a small amount of surfactant such as
triton X 100 to the fixative.
I would agree with Sharon that a controlled positive pressure helps in the
process but would recommend that you also include 0.01% -0.1% surfactant
in the fixative. This has been shown to decrease surface tension without
compromising routine histology. I am not sure if this has been used with
IHC but would be interested to hear some comments about this.
Another approach is to gently vacuum the fixative before use and use
gentle vacuum to remove the air, once  in the fixative.
I think that it is also advisable to vacuum infiltrate during paraffin
processing.
Barry

Katie B wrote:

> ---sbledsoe <sbledsoe@iupui.edu> wrote:
> >
> > I have been asked to Post the following:
> >
> > Could someone please suggest a good protocol for embedding lung
> tissue in
> > paraffin.
> >