DNA is extracted using a column-based method such as Qiagen’s QIAamp DNA Blood Mini Kit (Qiagen). Column methods are efficient, automatable, and have less chance of yielding samples with contaminants that could inhibit downstream applications. DNA will be dissolved in 10 mM Tris-HCL pH 8.0, 1mM EDTA (TE) (equivalent to Qiagen’s buffer AE). We use a NanoDrop ND-1000 Spectrophotometer to check the DNA concentration and purity.
Prepare and send specimens as per specifications below:
Acceptable sample types: whole blood (collected in Heparin coated tubes), plasma, serum, buffy coat, lymphocytes, body fluids, cultured cells, swabs, saliva, and tissue. Please do not send samples in tubes that are not appropriate for freezing.
For blood cells, buffy coat (a leukocyte-enriched fraction of whole blood) is the preferred sample. Preparing a buffy-coat fraction from whole blood is simple and yields approximately 5–10 times more DNA than an equivalent volume of whole blood. Blood is collected in a BD Vacutainer® CPT™ Cell Preparation Tube with Sodium Citrate and centrifuged at 2500 x g for 10 minutes at room temperature (15–25°C. After centrifugation, 3 different fractions are distinguishable: the upper clear layer is plasma; the intermediate layer is buffy coat, containing concentrated leukocytes; and the bottom layer contains concentrated erythrocytes.
- Prepare a sample sheet with the following information: Sample Id (samples anonymously coded), sample type, and any other pertinent information you choose to provide.
- One sample sheet for all samples. Comma separated CSV, Excel or tab delimited txt format is acceptable.
- Samples will be plated in a 96 well plate (8 by 12).
- This information will be provided on an Excel worksheet after the DNA extraction is complete: PLATE Name, POSITION, Sample Id, A260, A280, 260/280 ratio, DNA conc (ng/µL), DNA volume in plate (µL), and Total DNA amount (ng)
- DNA will be dissolved in 10 mM Tris-HCL pH 8.0, 1 mM EDTA (TE) (equivalent to Qiagen’s buffer AE).
- A copy of the IRB under which the samples were collected is required and methods must include processing and genotyping of samples.
Samples not following the above requirements will not be processed.
Standard Operating Procedures
Please contact us before you send your shipment. Send samples (in a styrofoam cooler on dry ice or ice packs overnight) with information to:
Saroja Voruganti, PhD
Core Director, Nutrigenetics Core
T: (704) 250-5009