Days Set Up
Monday - Friday, 8:00am - 5:00pm
Analytic Time

48 hrs - 3 weeks

Test Updated:



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Test Overview

Test Methodology
Test Usage

Evaluate muscle disease.

Reference Range

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Specimen Requirements

Collection Onsite

Call the muscle histochemist at 764-8170, one day in advance if you plan to have a muscle biopsy. The routine procedure for muscle biopsies at the University of Michigan includes standard paraffin sections (part 1) and a battery of histochemical procedures (part 2) used to differentiate fiber types and to help identify specific components. A specimen is also taken in case electron microscopic examination is needed (part 3). Each area should have Muscle Biopsy Kits with sterile containers, centrifuge tube, and Karnovsky's fixative (glutaraldehyde). Also each area has a metal Muscle Clamp for their use. If more kits are needed, please call 764-8170 at least 24 hours in advance. Cleaned, unsterilized clamps will be returned within 48 hours. Information is also available for ordering more muscle clamps. The muscle biopsy should be taken from the belly of the muscle and divided and prepared in the following manner by the operating room surgeon or staff: 1. The first piece, about 1.5 cm long x 1.0 cm wide, is to be stretched longitudinally on a piece of tongue blade using sutures tied at either end. This specimen is then to be placed specimen side down IN 10% FORMALIN labeled with the patient identification and 'Muscle biopsy - Part 1 for paraffin sections'. 2. The second piece of muscle will be used for histochemical stains. It should measure 1.5 cm in length and 1.0 cm in width. It is NOT TO BE STRETCHED, but simply placed on a saline moistened piece of gauze in a labeled specimen jar. DO NOT fix this specimen in formalin, allow it to dry out or let it float in water or saline, as these treatments will render the tissue useless for histochemical stains. Special care should be taken to obtain the full width required. 3. For electron microscopy on a muscle biopsy, a sterile muscle clamp should be used to clamp a 2 mm thick portion of muscle in situ. The clamp is attached to the muscle. The ends of the muscle are sutured external to the clamp and a cut made between the suture and the clamp. The special clamp with the attached specimen is then placed in a labeled centrifuge tube containing FRESH Karnovsky's fixative (supplied in kit). Call laboratory at 764-8170 for specimen pickup when all 3 parts are ready. All specimens must be accompanied by the appropriate requisition form containing the patient's complete name, registration number, service and location, physician's name and number, and pertinent clinical history. PLEASE NOTIFY LAB IF THE MUSCLE BIOPSY HAS BEEN CANCELLED.

Collection Offsite

Muscle Biopsy kits are available from MLabs and will be required in advance of the procedure. Please notify the MLABS Client Services Center at 800-862-7284 prior to sending specimen. Please complete a Muscle/Nerve/Renal Biopsy Requisition to accompany the specimen.
The muscle biopsy should be taken from the belly of a moderately affected muscle (avoid EMG and injection sites). Ideally, the biopsy is 2.5 - 3.0 cm in length x 1.0 cm in width for an adult or 2.0 cm in length x 0.5 cm in width for a child. Divide the muscle into three portions:
1. Fresh tissue should be sent only if the specimen can arrive at MLabs within 4 hours of collection, Monday - Friday, 7:00 am - 5:00 pm. Otherwise, tissue should be frozen (see below). Fresh Tissue: the first piece of muscle (1.5 x 1.0 cm) will be used for histochemical stains. Do not tease or pinch with forceps, or allow the tissue to dry out. Wrap the tissue in a saline-moistened Telfa pad and place in a screw-cap container. Do not immerse the tissue in saline. The container should be kept cold (on wet ice at refrigerator temperature); do not freeze. If the biopsy cannot be delivered to MLabs within 4 hours of collection, it should be processed in the following manner:
Frozen Tissue: (a) If liquid nitrogen is available, the specimen can be snap frozen by immersing it for 10-15 seconds in isopentane that has been frozen in liquid nitrogen. If isopentane is not available, roll the muscle gently in talc or glove powder, wrap it loosely in a piece of foil (do not flatten the muscle!), and immerse it into liquid nitrogen for 20 to 30 seconds. Place the frozen muscle in a Styrofoam container filled with dry ice or a -70 degrees C freezer until ready to ship. (b) If liquid nitrogen is not available, roll the muscle gently in talc or glove powder, wrap it loosely in a piece of foil (do not flatten the muscle!), and place in a Styrofoam container filled with dry ice.
2. Formalin Fixed Tissue: the second piece of muscle (approximately 1.0 x 1.0 cm) will be used for paraffin sections. Stretch the muscle longitudinally on a piece of tongue blade using sutures tied at either end, then place specimen side down in a container with 10% neutral buffered formalin (NBF). If the specimen is from a child, omit the formalin fixed specimen and provide two fresh (or frozen) specimens along with the glutaraldehyde fixed specimen. Specimen should be sent at room temperature; do not freeze.
3. Glutaraldehyde Fixed Tissue: the third piece of muscle (0.5 cm) will be used for electron microscopy. Use a metal clamp or small piece of a sterile wooden tongue blade (size of a toothpick) to suture to a 3 mm thin portion of muscle in situ. Place this sample with the clamp or tongue blade attached into a small vial containing 3% glutaraldehyde / 3% formaldehyde. Specimen should be sent at room temperature; do not freeze.
Ensure all containers are labeled with the patient's full name and a 2nd patient identifier. The formalin and glutaraldehyde fixed specimens must be shipped at room temperature, separate from cold or frozen material. Care must be taken that these specimens do not freeze. For detailed collection and shipping instructions, please see

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Our High Standard

Quality that sets us apart

As the reference laboratory division of Michigan Medicine's Department of Pathology, MLabs shares the institution's commitment to applying established quality principles to clinical laboratory testing. Like other large organizations in complex, consequential fields, we rely on an established approach to monitor quality throughout the testing process.