DNA requirements

Acceptable sources

DNA extracted from whole blood, buccal swab, saliva, fresh and frozen tissue, bone marrow, dried blood spots.

*We DO NOT accept DNA from Formalin-Fixed Paraffin-Embedded (FFPE) Tissue.*

**DNA MUST BE EXTRACTED IN A CLIA-certified Laboratory OR a laboratory meeting equivalent requirements as determined by the CAP and/or the CMS.**

Amount

5 µg (= 5,000 ng) DNA is sufficient for any one or two GeneDx tests, regardless of methodology, with exceptions mentioned below. If testing needs to be repeated for technical reasons or if there are an unusual number of positive findings to be confirmed, 5 µg may not be sufficient.

*DNA content should be determined by Qubit or other fluorometric method with a DNA-specific dye. If using absorbance or other methods, double the amount sent.*

**For International Clients: 10 µg (= 10,000 ng) of DNA is the required amount due to difficulty in obtaining additional/replacement specimen if needed.**

Amount exceptions

For domestic specimens, refer to the DNA Amount Exceptions table below for list of single gene tests that require a minimum of 8 µg of DNA.

Diluent

For best results, DNA should be dissolved in pH 8.0 TE buffer with low EDTA (10 mM Tris, 0.1 mM EDTA).
*Excess EDTA can inhibit reactions and must be avoided.*

Volume & concentration

The ideal specimen has a concentration of ≥50 ng/µL AND a volume of ≥100 µL.
*Specimens with concentrations over 250 ng/µL or volumes under 20 µL should be diluted before sending to avoid waste.*

Container

1.7 mL flip-cap microtube, 1.5 mL v-bottom screw cap tube, 0.5 mL v-bottom skirted tube or 2.0 mL v-bottom skirted tube is preferred.

Labeling

A minimum of two unique identifiers that match the paperwork MUST be provided on the specimen tube, such as the name/identifier of the person and date of birth. DNA concentration and volume MUST also be provided on the specimen tube.

Stability

Ship DNA in sealed and protective packaging at ambient temperature, using a cool pack in hot weather. Frozen DNA is also acceptable and should be shipped on dry ice.

Shipping

Ship at ambient temperature for overnight delivery with arrival Monday – Saturday to:

GeneDx, 207 Perry Parkway, Gaithersburg, MD 20877