Skin Punch Biopsy

Skin Punch Biopsy Collection and Shipping Instructions

GeneDx can isolate DNA directly from skin punch biopsies or from cultured fibroblasts. Genetic testing using cultured fibroblasts is required for patients who have had an allogeneic bone marrow transplant/stem cell transplant and is preferred for patients with a personal history of certain hematologic disorders – click here for more information. For the majority of cases culturing fibroblasts is successful; however, there are rare occasions when cells do not grow well and the DNA yield may not be sufficient to complete testing. In contrast, direct DNA isolation without culturing is preferred for gene sequencing in mosaic skin disorders.

Instructions: Please click here to view the full instructions for sample collection and shipping.
Exceptions: In general, any GeneDx test can be performed on genomic DNA from cultured fibroblasts, while DNA isolated directly from skin without culturing is suitable for sequencing but not usable for deletion/duplication tests. Completion of multiple tests or complex testing may depend on submission of the full amount requested.
Kits: Punch biopsy kits are available for US and Canadian clients. To order a kit, please email 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 samples 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.
Turn Around 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.