Collection Instructions for Epidermal Nerve Fiber Density (ENFD) Testing

Microscope ENFD testing orange background.webp

PUNCH BIOPSY PREPARATION & SITE SELECTION

Complete requisition form. Be certain to note date and time of collection. Make copies (both sides) of patient license & insurance card.

Print out patient label or fill out patient label provided in kit.

Wash hands. Choose leg biopsy site:

Proximal Thigh - 20 cm below the iliac spine, at the level of the pubis
Distal Leg (Calf) - 10 cm above the lateral malleolus

Write biopsy site on each patient label. Examples:

Left distal leg & right distal leg = 2 biopsies
Left proximal thigh & left distal leg = 2 biopsies

PATIENT LABELS

OFFICE PREPARATION

Provider office supplies the lidocaine with epinephrine, hemostatic agent, & topical antibiotic

PUNCH BIOPSY COLLECTION

After marking and prepping biopsy site, infiltrate lidocaine with epinephrine near biopsy site with inverted “V” pattern. Cleanse site with iodine prep pad.

Perform 3mm punch biopsy. Softly push punch instrument down while rotating back and forth. Enter the skin to the level of the subcutis, cutting through the epidermis and dermis.

Gently remove biopsy specimen using atraumatic forceps. Gently grasp the biopsy beneath the epidermis without crushing the surface. Use scissors to cut below the level of the dermis.

Place tissue specimen into Zamboni’s fixative (vial with orange cap) and follow the processing steps below.

Apply hemostatic agent, topical antibiotic, gauze, and bandage to the biopsy site.

Tissue from ENFD punch biopsy must be placed in Zamboni’s fixative for 8 hours, but not more than 24 hours.

Additional PROCESSING steps 4 through 7 are included if sample is not shipped on same day as collection

PROCESSING INSTRUCTIONS

Remove orange cap from collection tube. Using tweezers, place tissue in tube containing Zamboni’s fixative. Ensure tissue is fully submerged in fixative & replace cap tightly on tube.

Place patient label with punch site on the tube. Repeat steps above if second punch biopsy was performed.

If shipping same day, proceed to shipping instructions. If shipping next day, move forward with step 4 below.

Perform in-office rinse after tissue has been in fixative in the refrigerator for more than 8 hours (but less than 24 hours).

Remove orange tube cap & pour out Zamboni’s fixative into second tray. Do not remove the tissue specimen from original vial.

Refill tube with phosphate buffer prefill (clear cap). Rinse. Pour out. Refill tube with buffer prefill (clear cap) a second time. Rinse. Pour out.

Refill tube with Cryoprotectant prefill (blue cap) & replace cap tightly on tube.

Proceed to shipping instructions.

Freezer pack should be frozen solid prior to shipping

SHIPPING INSTRUCTIONS

Place tubes with tissue specimens inside biohazard bag & seal bag.

Place requisition form & patient forms in pocket on outside of biohazard bag.

Be sure to note the shipping solution on the requisition form:

Zamboni's fixative OR
Fixed, rinsed in PBS & placed in Cryoprotectant

Place biohazard bag and frozen freezer pack inside styrofoam box.

Place styrofoam box inside original kit box. Place kit box inside pre-paid return mailer and seal.

Immediately put shipping package in the refrigerator until ready for pickup.