[Histonet] Mixed fiber type identification

[mtitford <@t> aol.com]

Arjun Ruhella asked about fiber typing of animal soleus muscle:

No one answered him, at least in public. I guess all the hotshots are in Vancouver!

Years ago I was involved in fiber typing and measuring of human muscle biopsy fibers. In those human muscle biopsies, all the bundles were mixed, about 60:40 if I remember correctly. The proportion and size of the fibers changed depending on the disease process.

We used the ATP reaction  on frozen sections to visualise the type 1 and type II, (and IIA, IIB, etc) fibers. Then, in those pre-computer days, we selected a typical muscle bundle and started counting the cross sectional diameter of those type I and type II fibers, using eypepiece graticule in the microscope. A histogram was prepared.

I cannot imagine using IHC to demonstrate the type I and Type II fibers is a whole lot different, or that animals have muscle fibers that are not mixed. 

You can see some differentiation on a good PAS  stain, but I do not know how  well it compares.

The procedure we used was in "Muscle Biopsy: A modern approach" by Dubrowitz and Brooke, Saunders. 1973  ( I told you it was years ago!)

Hope this helps

Michael Titford
Pathology - USA
Mobile AL