Muscle Biopsy Specimen

Call Client Services at 773.702.8287 when a biopsy is scheduled so we can begin preparing for the specimen.

Muscle biopsy

Muscle biopsies are usually reported back the next working day for routine inflammatory myopathies and denervation. Myopathies requiring additional histochemistry or electron microscopy may require an additional week.

Patient information 

Attach any pertinent information, such as the suspected clinical diagnosis, serum creatine kinase level, results for collagen vascular disease enzymes, electromyographic (EMG) studies, and specific neurologic findings.

Include the address(es) and fax number where results should be sent as well as the name of the ordering pathologist.

We do not reject any specimens, but physicians are notified upon receipt of inadequate specimens.

Collection requirements and precautions

Obtain a biopsy from a muscle that is definitely affected but not so severely affected that much of it is replaced by fatty or fibrous connective tissue.

  • The involved muscle should not have been previously traumatized by injections or by EMG studies.
  • Typically, the triceps, biceps, or vastus lateralis is chosen.

The biopsy should be approximately 1.5 cm x 0.5 cm and dissected with minimal trauma along the long axis of the muscle fibers. If extra studies are needed, then another piece of similar size should be obtained.

  • Do not use electrocautery or a muscle clamp in removing the specimen.
  • If a muscle biopsy is received in a clamp or other apparatus, remove the specimen from it immediately.

Fresh muscle and nerve biopsies should be delivered to Anatomic Pathology as soon as possible after they are excised from the patient. All attempts should be made to have the biopsy reach the lab within two hours after removal.

Freezing Method Requirements and Precautions

When freezing, use one of the two approved methods listed below and:

  • Freeze the specimen so all fibers are oriented in the same direction.
  • The specimen should be blotted with an absorbent towel to extract excess moisture before flash freezing.
  • Do not use a mounting medium such as optimal cutting temperature (OCT) compound when freezing the specimen.
  • Do not leave forceps impressions in the muscle.
  • Do not use pins, needles, tongue depressors, or a muscle clamp.
  • Do not wrap muscle in tinfoil.
  • A well-frozen specimen should have a white, chalky color.
  • Never place the frozen specimen in a non-chilled container, as the specimen will thaw before it freezes again.
  • The specimen can be stored at -70°C but must not thaw between the time of initial freezing and shipment.

Note: If the biopsy is taken on a Friday, flash freeze using one of the approved methods and store at -70°C until the specimen can be sent the following Monday.

Method 1

Isopentane- liquid nitrogen freezing (preferred)

  • Puncture the lid of a screw-cap specimen container to allow excess isopentane to evaporate.
  • Place the plastic screw-cap specimen container in a -70°C freezer or on dry ice to pre-chill.
  • Add 50–100 mL of isopentane (2-methylbutane) to a Nalgene or metal beaker. Suspend the beaker in a bath of liquid nitrogen and wait until the isopentane freezes to a white, chalky substance. Remove the beaker from the nitrogen bath. Carefully drop or set the muscle on the frozen isopentane while keeping the muscle fibers straight and running in the same direction.
  • The isopentane will start to thaw as soon as it contacts the warmer muscle specimen. At this point, it is important to swirl the beaker around so that the specimen will continue to contact the colder, frozen isopentane.
  • The total freezing period should take approximately 10 to 15 seconds.
  • After removing the specimen from the isopentane, immediately place the tissue in the container that has been pre-chilled on dry ice. Do not wrap it in foil.
  • Place a cover on the container.
  • Keep the specimen frozen at -70°C or on dry ice from this point on.

Method 2

Slurry Method

  • Puncture the lid of a screw-cap specimen container to allow excess alcohol/acetone to evaporate.
  • Place the plastic screw-cap specimen container in a -70°C freezer or on dry ice to pre-chill.
  • Wrap solid dry ice in a towel, pulverize it with a hammer, and then pour the powder to fill a 200 mL beaker.
  • Slowly add 100 percent alcohol or acetone and stir the mixture. At least 80 percent of the total volume of the slurry should consist of dry ice and only 20 percent of alcohol/acetone.
  • When the slurry nearly stops bubbling, its temperature has fallen to about -70°C and it is suitable for flash freezing. Keep adding dry ice as needed to reach this point. The final product should resemble a snow cone.
  • Hold the biopsy specimen with forceps and plunge it into the slurry quickly. Swirl the specimen in the slurry for 10 to 15 seconds, remove it, and quickly blot it dry with an absorbent towel to remove excess alcohol/acetone.
  • Immediately place the tissue in a specimen container that has been pre-chilled on dry ice. Do not wrap it in foil.
  • Place a cover on the container.
  • Keep the specimen frozen at -70°C or on dry ice from this point on.

Note: Avoid prolonged immersion of the specimen in the quenching mixture, as it then becomes permeated with alcohol or acetone, which inhibits enzyme studies by histochemical methods.

Packaging

Use the muscle biopsy shipping kit to deliver. Call 773.702.8287 to order a kit.

  • Place the transport vial with the flash-frozen specimen in the yellow frozen tissue bag with an absorbent cloth and seal the bag.
  • Place the completed muscle histochemistry patient information sheet and any appropriate clinical history in the pocket of the bag.
  • Store the specimen in a -70°C freezer or liquid nitrogen until it is retrieved by a courier or it is ready to be prepared for shipping to UChicago Medical Laboratories.

Shipping

Send on a Monday, Tuesday, Wednesday, or Thursday only.

If using a courier service:

  • One day before shipping, contact client services at 773.702.8287 and ask for transportation.
  • Alert transportation that a muscle biopsy will be shipped from your institution.
  • Transportation will notify your courier to bring extra dry ice for packaging (if sending a pre-frozen sample).
  • Fresh samples need to be delivered to the lab within two hours of removal from the patient. 

Delivery instructions

Muscle biopsies should be delivered to Anatomic Pathology as soon as possible after they are excised from the patient. All attempts should be made to have the biopsy reach the lab within two hours after removal.

The driver should deliver to:

Peter Pytel, MD
Anatomic Pathology
Room J-601
5812 South Ellis Ave.
Chicago, IL 60637
Phone: 773.702.8287

The delivery information should be on the outside of the package. No specimen will be received after 3:30 p.m. unless previously approved by the neuropathology on-call physician (Dr. Peter Pytel at 773.795.6751).

If shipping via FedEx (must be priority overnight):

  • Pack the specimen in 8 to 10 lb. of pellet or small-particle dry ice so it is surrounded by ice.
  • Send the specimen using express overnight delivery on Mondays, Tuesdays, Wednesdays, or Thursdays only. If the specimen is collected on a Friday, hold it in a -70°C freezer or liquid nitrogen until it can be shipped the following Monday.

Shipping address:

Bright Star Logistics
Attn: UCMC Lab
7800 S. Quincy St.
Willowbrook, IL 60627 

Contact Us

For questions related to specimen preparation contact:

Department of Pathology Client Services

Phone: 773.702.8287 and mention that you are inquiring about sending a fresh or frozen muscle and/or nerve biopsy
Fax: 773.702.4633

To review clinical problems with the clinician before the biopsy is performed contact:

Peter Pytel, MD
Phone: 773.795.6751

For muscle biopsy shipping kits contact:
Phone: 773.702-8287