Re: Muscle Biopsy Clamps

From:Vinnie Della Speranza <>

thank you for sharing your muscle biopsy protocol with us. I am in complete agreement with your remarks regarding the value of requesting sufficient samples at biopsy.
you may be interested to know that I have achieved acceptable EM results by using 4% paraformaldehyde fixative which has allowed us to get by with one clamped specimen, in addition to the unfixed sample for enzyme histochemistry. This fixative eliminates the methanol contained in commercial formalin/formaldehyde solutions that can compromise EM. You may experience less resistance from clinicians if you can get by with only two samples.

Vinnie Della Speranza
Manager for Anatomic Pathology Services
Medical University of South Carolina
165 Ashley Avenue
Suite 309
Charleston, SC  29425
ph:  (843) 792-6353
fax: (843) 792-8974

>>> <> 03/31/01 08:57PM >>>
Peggy et. al.,
Our protocol (from Dr. Sumi @ U. of W. neuropath) requests the following for 
neuropathathology workup on a muscle biopsy:
       1.  One biopsy "unclamped" for muscle enzyme histochemistry (Note, for 
the           reasons of clamp artifact and the desired uncrushed relaxation 
of  the fibers, as you noted.)  This portion is snap frozen in a relaxed 
state @ -160 degrees C. in  Isopentane cooled by liquid nitrogen.
       2.  A 2nd biopsy in a clamp and allowed to fix in this state in 10% 
NBF for 24 hours before resection of the "uncrushed" portion of the biopsy 
from between the tines of the clamp(for routine L.M. if needed).
       3.  A 3rd biopsy (as in #2 above) but in Trump's fixative for E.M. if 
Our feeling is that if the patient is going to undergo an open biopsy 
procedure we should harvest all materials necessary for a complete and 
definitve neuropathology assessment.  The only time we compromise on these 
specimen requirements are when the patient is a pediatric or a Shriner's 
patient when there is concern for the amount of the muscle compromise to the 
young patients.  I understand that often not all three of these specimens are 
necessary for diagnosis, but after getting the patient all the way into an 
invasive surgical procedure, which is for the sole purpose of obtaining a 
tissue diagnosis,  I would advocate a multiple bx/fixative approach.
Greg Luck
Anat.Path. Sup.
Deaconess Med Center
Spokane, WA

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