Skin punch biopsy requirements

Skin punch biopsy collection and shipping instructions

GeneDx can isolate DNA directly from skin punch biopsies or from cultured fibroblasts. For patients who pursue genetic testing, DNA from cultured fibroblasts is the required specimen type if the patient has had an allogeneic bone marrow/stem cell transplant and is preferred for patients with certain hematologic malignancies. Direct DNA isolation without culturing may be preferred for other disorders, such as mosaic skin disorders.

Contact zebras@genedx.com with any questions prior to specimen submission.

GeneDx can provide a punch biopsy kit and can culture fibroblasts on site as needed.

Kits

Punch biopsy kits are available for US and Canadian clients. To order a kit, please email zebras@genedx.com or call us at 888-728-1206/301-519-2100. Contents include 15mL tube of RPMI media, label for tube, and prepaid return FedEx packaging. Note that kits must be refrigerated once they arrive at their destination to prevent the RPMI media from spoiling. Kits include an expiration date, typically several weeks out from the date of shipment.

Specimen Size

One or two 4mm skin punch biopsies. Biopsies may be collected from any site of healthy skin. One punch typically provides ample DNA for genetic testing; however, a second specimen increases the likelihood of successfully culturing. For mosaic skin disorders, be sure to biopsy an affected (lesional) area and always send two punches of 4-6 mm or excised skin of an equivalent area.

Labeling

Label with the patient name and date of birth.

Stability & shipping

Skin biopsy specimens must be shipped at room temperature for overnight delivery to GeneDx the same day as the biopsy is performed. Note that specimens are accepted by the lab on Saturdays. For DIRECT DNA ISOLATION only, if shipping must be postponed, biopsies can be flash frozen and shipped frozen at a later time.

Turnaround time

Published turn-around times do not apply for punch biopsy specimens due to the time needed to culture fibroblasts. In general cell culturing adds 2 weeks to published turn-around times.