Therapath Neuropathology

Muscle biopsy procedure

Biopsy kits

Muscle biopsy kits include the following components:

  • Foam insulating container and shipping box
  • Pre-paid shipping label and requisition form
  • Coolant pack (store in a freezer no colder than -20° C)
  • Transport bag holding:
    • Vial 1: Empty vial for fresh, unfixed tissue
    • Vial 2: 10% neutral buffered formalin
    • Vial 3: 2.5% glutaraldehyde/2.0% formaldehyde

Upon receipt, place the coolant pack in the freezer (no colder than -20° C)  and store the remainder of the kit at room temperature (22-25° C). After addition of biopsy specimens, the entire box containing all vials should be prepared for shipment and kept cool with the provided coolant pack.


Sample Collection

Adults: Excise a 1 cm x 1 cm x 2.5-3.0 cm longitudinal length of muscle. Do not stretch the muscle and handle gently only by the ends.

Young Children: Similarly excise and handle a 0.5 cm x 0.5 cm x 2.0-2.5 cm length of muscle.


Sample Preparation

Divide the biopsy, place into vials as follows, and cap all vials tightly.

A) Segment 1 (for enzyme histochemistry and immunohistochemistry)
1 cm cube (adult) or 0.5 cm cube (young children):
Remove the single 2” × 2″ gauze pad from its pouch in the sterile accessory kit and slightly dampen it with normal saline (not provided). Manually squeeze out excess saline until the gauze is just moist (not wet). Unfold the gauze to the original size, place the muscle segment near one edge and roll the gauze around the muscle to wrap it. Make a shallow fold at both ends to completely enclose the tissue. Carefully insert the wrapped biopsy vertically into the empty vial 1 (green label) without squeezing or pressure on the tissue specimen.*

*Do not use more than the one 2” × 2” gauze pad to wrap the biopsy, or make too many overlapping folds, or use a biopsy segment that is wider than 1 cm cube as the resulting extra thickness may cause excessive compression of the tissue during insertion into the vial opening.

b) Segment 2 (for routine histology)
1 cm cube (adult) or 0.5 cm cube (young children):
Place this segment into vial 2 (white cap) containing 10% neutral buffered formalin.

c) Segment 3 (for EM)
No larger than 0.3 cm x 0.3 cm x 0.5 cm:
Place this segment into vial 3 (yellow cap) containing 2.5% glutaraldehyde/2.0% formaldehyde, making sure that the muscle is immersed in the fixative.


Preparation for Shipment

  1. Use one collection kit per muscle or nerve specimen.
  2. Complete the requisition form.
  3. Label vials with patient name and biopsy site using the provided labels.
  4. Insert labeled vials in foam holder, and place in biohazard 95kPA bag. Place sealed bag in foam cooler along with a frozen icepack.
  5. Enclose foam cooler and completed requisition in cardboard kit box. Seal box inside of pre-labeled UPS or FedEx return bag.
  6. Call the shipping service to schedule a pickup. When calling, say “representative” and “bill third party” to request an on-demand pickup.
    • For UPS, call 800.823.7459
    • For FedEx, call 800.463.3339
  7.  Include a frozen ice pack with return shipment to Therapath