Question: How do I extract genomic DNA from blood or cell culture?
Answer: We have validated a number of methods for obtaining HMW gDNA from cells and whole blood, including:
- QIAGEN MagAttract protocol: We have made several minor modifications to the standard protocol that significantly improve DNA quality, with the majority of extracted gDNA >50 kb on a pulsed-field gel. The modified extraction protocol can be found in the User Guide for the Chromium Genome Reagent Kit v2: https://support.10xgenomics.com/genome-exome/index/doc/user-guide-chromium-genome-reagent-kit-v2-chemistry. A protocol for obtaining HMW gDNA specifically from whole blood using MagAttract is described here: http://support.10xgenomics.com/genome-exome/sample-prep/doc/demonstrated-protocol-hmw-dna-extraction-from-whole-blood
- Salting Out Method for DNA Extraction from Cells: This method can produce gDNA with an average size of >200 kb when analyzed on a pulsed-field gel. After the Chromium Genome Assay, the average size of the library inserts is >80 kb as measured by Long Ranger. Our protocol uses suspension cells, but we expect similar results from adherent cells: https://support.10xgenomics.com/genome-exome/sample-prep/doc/demonstrated-protocol-salting-out-method-for-dna-extraction-from-cells
Notes on blood storage:
- We have stored whole blood at 4°C for up to 3 days prior to DNA extraction with no adverse effects.
- Successful results have also been demonstrated using whole blood collected in an EDTA purple cap tube and stored for 1 month at either −20°C or −80°C.
- For long-term storage, we have tested storing blood samples at -135°C in vapor phase liquid N2 by aliquoting 1ml of blood from the EDTA tube into standard 1.8 ml cryotubes and storing them in a cryotank for > 1 year.
Products: Genome, Exome