Open biopsy strongly indicated for disorders with patchy pathology, e.g. polymyositis Do not use cautery, sutures, or clamps.
Some laboratories use needle for many biopsies to minimize trauma.
Keep specimen cool. Muscle should NOT be immersed in saline, fixative or other liquids. Frozen muscle for histochemistry provides Excellent muscle fiber morphology Most diagnostic information with light microscopy Freezing process should be rapid to prevent artifact.