1. Sample Collection
<ol>
 <li>Collect blood samples from individuals with proper informed consent. For each individual, draw 4 to 5 ml of blood into a P100 tube (BD Diagnostics, Franklin Lake, NY, USA). For comparison purposes, simultaneously collect blood in an EDTA tube.</li>
 <li>The BD P100 tubes contain 15.8 ml spray-dried K2EDTA and a lyophilized proprietary broad spectrum cocktail of protease inhibitors to prevent coagulation and stabilize the plasma proteins. They also contain a mechanical separator. After collecting the whole blood, keep both tubes at room temperature for 60 min to overnight until processing occurs.</li>
 <li>Centrifuge the BD P100 tubes at 2,500 g for fifteen minutes at room temperature. Transfer the plasma collected above the mechanical separator into micro centrifuge tubes.</li>
 <li>Store the P100 tubes, containing the blood compacted below the separator, at -80 &deg;C until you are ready to begin the DNA extraction.</li>
</ol>
2.1 From blood of P100 tube (P100_DNA)
<ol>
 <li>The P100 tubes are stored at -80 &deg;C after plasma extraction. Within 3 to 4 months, retrieve the P100 tube containing the compacted blood from the freezer and thaw at 37 &deg; in a water bath for 5 min (Figure 1A). Remove any residual plasma that sits above the separator. Add 2 ml of 17% sucrose solution (gradient solution tested in house - unpublished data) in the P100 tubes above the separator (Figure 1B). Centrifuge the tubes at room temperature for 20 min at 2,500 g; this process pushes the mechanical separator to the top of the tube and yields three layers of solution including the buffy coat (Figure 1C). Manually extract the separator using a steriled hooked metal paperclip (Figure 1D).</li>
 <li>After retrieving the mechanical separator from each tube (Figure 1D), remove and discard the top sucrose layer. Transfer the middle layer, representing the buffy coat (BC) layer, into a sterile 15 ml conical tube. Add Phosphate Buffer Saline (PBS) to increase the buffy coat volume to 3 ml. Extract the DNA from the buffy coat using reagents from the Qiagen Puregene Blood Kit as per the manufacturer's recommendation; except a centrifugation speed of 2,500 g (instead of 2,000 g).</li>
 <li>To lyse and remove the red blood cells (RBC), add 9 ml of RBC lysis to 3 ml of buffy coat. Invert each tube several times and incubate at room temperature for 10 min with occasional inverting during incubation. Spin each mixture down at 2,500 g for 5 min and discard the supernatant. Treat the remaining pellet in each tube with 3 ml of cell lysis solution and vortex for 15 sec. Treat the lysate with 1 ml of protein precipitation solution and vortex for 15 sec.</li>
 <li>Centrifuge at 2,500 g for 5 min and transfer the supernatant into a fresh 15 ml conical tube containing 3 ml of 100% isopropanol. Invert the new tubes 10 times and centrifuge at 2,500 g for 3 min. Discard the supernatant and add 1 ml of 70% ethanol. Invert the conical tubes a few times to dislodge and wash the DNA pellet. Centrifuge at 2,500 g for 1 min. Allow the pellet to dry for 3 min (place the tube upside down) at room temperature and then suspend the DNA with 250 ml of rehydration solution at 37 &deg;C for 10 min and transfer to a pre-labeled 1.7 ml microtube. Store the tubes at -80 &deg;C until use.</li>
</ol>
2.2 From Blood of EDTA Ttube (EDTA_DNA)
<ol>
 <li>The whole blood for routine immunohematology testing is collected in plastic vaccutainer tubes spray-coated with 10.8 mg of K2EDTA and stored at -80 &deg;C. Because the tubes do not contain a mechanical separator, the DNA extraction does not include the steps involving the mechanical separator (2.1.1 and 2.1.2).</li>
 <li>Within 3 to 4 months of blood storage, the DNA is extracted using the KingFisher Flex (Thermo Fisher Scientific, Waltham, MA, USA). It is an automation DNA extraction system based on magnetic particle technology and consists of cell lysis / DNA binding, several washing steps and DNA elution.</li>
 <li>The kit used in the DNA extraction is the KingFisher Flex 24 DNA Blood kit (Qiagen, Germany).</li>
</ol>
3. DNA Quantity and Quality Assessment
The quantity, quality and integrity of the genomic DNA were assessed by a combination of method that includes picogreen, spectroscopy and electrophoresis.
<ol>
 <li>The concentration of the genomic DNA is determined by Nanodrop and picogreen quantification.</li>
 <li>The purity is determined from the 260/280 ratio measurement on the Nanodrop spectrophotometer.</li>
 <li>The sample (500 ng) is also loaded on 1% agarose gel to assess the integrity (degradation) of the DNA.</li>
</ol>
4. Genotyping Assays and Quality Control 
<ol>
 <li>Five P100_DNA and their corresponding EDTA_DNA samples are randomly selected for further analysis using the custom Immunochip (Immuno DNA Analysis BeadChip). Immunochip is an Infinium genotyping chip containing 196,524 polymorphisms and is designed for immunogenetic studies5.</li>
 <li>For each sample, 200 ng of DNA is amplified, fragmented, precipitated and resuspended in the appropriate hybridization buffer.</li>
 <li>The denatured samples are hybridized on Immunochips at 48 &deg;C for a minimum of 16 hr.</li>
 <li>After hybridization, the Immunochips are processed for single-base extension reactions and stained.</li>
 <li>The immunochips are then imaged using Illumina Hiscan Bead array reader and the normalized bead intensity data is loaded into the Illumina GenomeStudio software and converted into genotypes. Genotypes are called using the autocalling algorithm of GenomeStudio. The quality control involves exclusion of single nucleotide polymorphisms (SNPs) with a call rate &lt;95%.</li>
 <li>The SNP call rate is used as a measure of the immunochip assay efficiency. It is calculated as the percentage of the total number of assays on the chip (196,524 SNPs encoded on each chip) that achieve sufficient signal intensity and quality to receive an automated genotype assignment. High quality DNA (260/280 ratio of 1.8 or higher and absence of degradation) is expected to achieve at least the same call rate as the HapMap control DNA included in the immunochip assay. Quality control involves exclusion of SNPs with a call rate &lt;95% in each data set.</li>
</ol>

<ol>
	<li>Yi, J., Kim, C., Gelfand, C. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inhibition+of+intrinsic+proteolytic+activities+moderates+preanalytical+variability+and+instability+of+human+plasma.">Inhibition of intrinsic proteolytic activities moderates preanalytical variability and instability of human plasma.</a> Journal of Proteome Research. 6, 1768-1781 (2007).</li><li>Garg, U. C., Hanson, N. Q., Tsai, M. Y., Eckfeldt, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simple+and+rapid+method+for+extraction+of+DNA+from+fresh+and+cryopreserved+clotted+human+blood.">Simple and rapid method for extraction of DNA from fresh and cryopreserved clotted human blood.</a> Clinical Chemistry. 42, 647-648 (1996).</li><li>Salazar, L. A., Hirata, M. H., Cavalli, S. A., Machado, M. O., Hirata, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+procedure+for+DNA+isolation+from+fresh+and+cryopreserved+clotted+human+blood+useful+in+clinical+molecular+testing.">Optimized procedure for DNA isolation from fresh and cryopreserved clotted human blood useful in clinical molecular testing.</a> Clinical Chemistry. 44, 1748-1750 (1998).</li><li>Xu, R., Ye, P., Luo, L., Wu, H., Dong, J., Deng, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+and+efficient+method+for+DNA+purification+from+samples+of+highly+clotted+blood.">A simple and efficient method for DNA purification from samples of highly clotted blood.</a> Molecular Biotechnology. 46, 258-264 (2010).</li><li>Cortes, A., Brown, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Promise+and+pitfalls+of+the+Immunochip.">Promise and pitfalls of the Immunochip.</a> Arthritis Research &amp; Therapy. 13, 101 (2011).</li><li>Basuni, A. A., Butterworth, L. A., Cooksley, G., Locarnini, S., Carman, W. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+efficient+extraction+method+from+blood+clots+for+studies+requiring+both+host+and+viral+DNA.">An efficient extraction method from blood clots for studies requiring both host and viral DNA.</a> Journal of Viral Hepatitis. 7, 241-243 (2000).</li><li>Kanai, N., Fujii, T., Saito, K., Tokoyama, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+and+simple+method+for+preparation+of+genomic+DNA+from+easily+obtainable+clotted+blood.">Rapid and simple method for preparation of genomic DNA from easily obtainable clotted blood.</a> Journal of Clinical Pathology. 47, 1043-1044 (1994).</li><li>Adkins, K. K., Strom, D. A., Jacobson, T. E., Seemann, C. R., O'Brien, D. P., Heath, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Utilizing+genomic+DNA+purified+from+clotted+blood+samples+for+single+nucleotide+polymorphism+genotyping.">Utilizing genomic DNA purified from clotted blood samples for single nucleotide polymorphism genotyping.</a> Archives of Pathology &amp; Laboratory Medicine. 126, 266-270 (2002).</li><li>Siafakas, N., Burnett, L., Bennetts, B., Proos, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonenzymatic+extraction+of+DNA+from+blood+collected+into+serum+separator+tubes.">Nonenzymatic extraction of DNA from blood collected into serum separator tubes.</a> Clinical Chemistry. 41, 1045-1046 (1995).</li><li>Everson, R. B., Mass, M. J., Gallagher, J. E., Musser, C., Dalzell, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extraction+of+DNA+from+cryopreserved+clotted+human+blood.">Extraction of DNA from cryopreserved clotted human blood.</a> BioTechniques. 15, 18-20 (1993).</li><li>Se Fum Wong, S., Kuei, J. J., Prasad, N., Agonafer, E., Mendoza, G. A., Pemberton, T. J., Patel, P. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+method+for+DNA+isolation+from+clotted+blood+extricated+rapidly+from+serum+separator+tubes.">A simple method for DNA isolation from clotted blood extricated rapidly from serum separator tubes.</a> Clin. Chem. 53, 522-524 (2007).</li><li>Garg, U. C., Hanson, N. Q., Tsai, M. Y., Eckfeldt, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simple+and+rapid+method+for+extraction+of+DNA+from+fresh+and+cryopreserved+clotted+human+blood.">Simple and rapid method for extraction of DNA from fresh and cryopreserved clotted human blood.</a> Clin. Chem. 42, 647-648 (1996).</li><li>Salazar, L. A., Hirata, M. H., Cavalli, S. A., Machado, M. O., Hirata, R. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+procedure+for+DNA+isolation+from+fresh+and+cryopreserved+clotted+human+blood+useful+in+clinical+molecular+testing.">Optimized procedure for DNA isolation from fresh and cryopreserved clotted human blood useful in clinical molecular testing.</a> Clin. Chem. 44, 1748-1750 (1998).</li><li>Matheson, L. A., Duong, T. T., Rosenberg, A. M., Yeung, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assessment+of+sample+collection+and+storage+methods+for+multicenter+immunologic+research+in+children.">Assessment of sample collection and storage methods for multicenter immunologic research in children.</a> Journal of Immunological Methods. 339, 82-89 (2008).</li><li>Xu, R., Ye, P., Luo, L., Wu, H., Dong, J., Deng, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simple+and+efficient+method+for+DNA+purification+from+samples+of+highly+clotted+blood.">A simple and efficient method for DNA purification from samples of highly clotted blood.</a> Mol. Biotechnol. 46, 258-264 (2010).</li><li>Polychronakos, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fine+points+in+mapping+autoimmunity.">Fine points in mapping autoimmunity.</a> Nature. 43, 1173-1174 (2011).</li><li>Cooper, J. D., Simmonds, M. J., Walker, N. M., Burren, O., Brand, O. J., Guo, H., Wallace, C., Stevens, H., Coleman, G., Franklyn, J. A., Todd, J. A., Gough, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seven+newly+identified+loci+for+autoimmune+thyroid+disease.">Seven newly identified loci for autoimmune thyroid disease.</a> Human Molecular Genetics. , (2012).</li></ol>

No conflicts of interest declared.

Many human diseases have genetic causes and exploring the genetic basis of human disease demands an increasing high quality DNA. The most common source of DNA used in genetic studies is anticoagulated whole blood. Because most clinical laboratories perform biochemical, serologic, and viral testing as a first step in phenotypic outcome investigation, the blood is often collected in a plasma tube. After collection of the plasma, the compacted blood is often discarded. Therefore, when DNA is needed to conduct gen...

<table border="1">
 <tbody>
 <tr>
 <td>Name of the reagent/equipment</td>
 <td>Company</td>
 <td>Catalogue number</td>
 </tr>
 <tr>
 <td>BD P100 tubes</td>
 <td>BD Diagnostics</td>
 <td>366448</td>
 </tr>
 <tr>
 <td>EDTA tubes</td>
 <td>BD Diagnostics</td>
 <td>367863</td>
 </tr>
 <tr>
 <td>Sucrose</td>
 <td>Sigma</td>
 <td>S9378</td>
 </tr>
 <tr>
 <td>Paper clip</td>
 <td>Office product</td>
 <td></td>
 </tr>
 <tr>
 <td>15 ml tube</td>
 <td>Corning</td>
 <td>430052</td>
 </tr>
 <tr>
 <td>Red blood cells (RBC)</td>
 <td>Qiagen</td>
 <td>158389 (kit)</td>
 </tr>
 <tr>
 <td>Phosphate Buffer Saline (PBS)</td>
 <td>Thermo Scientific</td>
 <td>SH30256.01</td>
 </tr>
 <tr>
 <td>BioSprint 96 DNA Blood Kit (48) </td>
 <td>Qiagen</td>
 <td>940054</td>
 </tr>
 <tr>
 <td>1.7 ml microtubes</td>
 <td>Axygen</td>
 <td>MCT-175-C</td>
 </tr>
 <tr>
 <td>Human Immuno DNA Analysis BeadChip Kit</td>
 <td>Illumina</td>
 <td>WG-352-1001</td>
 </tr>
 <tr>
 <td>Bead array reader</td>
 <td>Illumina</td>
 <td>NA</td>
 </tr>
 <tr>
 <td>GenomeStudio Software</td>
 <td>Illumina</td>
 <td>N/A</td>
 </tr>
 </tbody>
</table>

a practical and novel method to extract genomic dna from blood collection kits for plasma protein preservation

Laboratory tests can be done on the cellular or fluid portions of the blood. The use of different blood collection tubes determines the portion of the blood that can be analyzed (whole blood, plasma or serum). Laboratories involved in studying the genetic basis of human disorders rely on anticoagulated whole blood collected in EDTA-containing vacutainer as the source of DNA for genetic / genomic analysis. Because most clinical laboratories perform biochemical, serologic and viral testing as a first step in phenotypic outcome investigation, anticoagulated blood is also collected in heparin-containing tube (plasma tube). Therefore when DNA and plasma are needed for simultaneous and parallel analyses of both genomic and proteomic data, it is customary to collect blood in both EDTA and heparin tubes. If blood could be collected in a single tube and serve as a source for both plasma and DNA, that method would be considered an advancement to existing methods. The use of the compacted blood after plasma extraction represents an alternative source for genomic DNA, thus minimizing the amount of blood samples processed and reducing the number of samples required from each patient. This would ultimately save time and resources.
The BD P100 blood collection system for plasma protein preservation were created as an improved method over previous plasma or serum collection tubes1, to stabilize the protein content of blood, enabling better protein biomarker discovery and proteomics experimentation from human blood. The BD P100 tubes contain 15.8 ml of spray-dried K2EDTA and a lyophilized proprietary broad spectrum cocktail of protease inhibitors to prevent coagulation and stabilize the plasma proteins. They also include a mechanical separator, which provides a physical barrier between plasma and cell pellets after centrifugation. Few methods have been devised to extract DNA from clotted blood samples collected in old plasma tubes2-4. Challenges from these methods were mainly associated with the type of separator inside the tubes (gel separator) and included difficulty in recovering the clotted blood, the inconvenience of fragmenting or dispersing the clot, and obstruction of the clot extraction by the separation gel.
We present the first method that extracts and purifies genomic DNA from blood drawn in the new BD P100 tubes. We compare the quality of the DNA sample from P100 tubes to that from EDTA tubes. Our approach is simple and efficient. It involves four major steps as follows: 1) the use of a plasma BD P100 (BD Diagnostics, Sparks, MD, USA) tube with mechanical separator for blood collection, 2) the removal of the mechanical separator using a combination of sucrose and a sterile paperclip metallic hook, 3) the separation of the buffy coat layer containing the white cells and 4) the isolation of the genomic DNA from the buffy coat using a regular commercial DNA extraction kit or a similar standard protocol.

DNA quality assessment and concentration measurement
The yields of P100_DNAs were significantly lower than those of EDTA_DNAs (Tables 1 and 2). The DNA purity represented by its 260/280 ratio value is similar for both P100_DNA and EDTA_DNA sample set (Tables 1 and 2). The quality of the DNA is fairly uniform within each set of sample although some degradation is seen in the EDTA_DNA samples, as indicated by light smear (<str...

Watch this Scientific Journal Video about A Practical and Novel Method to Extract Genomic DNA from Blood Collection Kits for Plasma Protein Preservation at JoVE.com

A Practical and Novel Method to Extract Genomic DNA from Blood Collection Kits for Plasma Protein Preservation

We are describing a new method of isolating genomic DNA from whole blood collected for plasma/serology. After plasma collection, the compacted blood is usually discarded. Our novel method represents a significant improvement over existing methods and makes DNA and plasma available from a single collection, without requesting additional blood.

Laboratory tests can be done on the cellular or  fluid portions of the blood. The use of different blood collection tubes  determines the portion of the ...

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41.9K Views.  Emory University School of Medicine and Children's Health Care of Atlanta. We are describing a new method of isolating genomic DNA from whole blood collected for plasma/serology. After plasma collection, the compacted blood is usually discarded. Our novel method represents a significant improvement over existing methods and makes DNA and plasma available from a single collection, without requesting additional blood.

Video: A Practical and Novel Method to Extract Genomic DNA from Blood Collection Kits for Plasma Protein Preservation

Isolation of Genomic DNA from Mouse Tails

Blood Collection from the American Horseshoe Crab, Limulus Polyphemus

The horseshoe crab has the best-characterized immune system of any long-lived invertebrate. The study of immunity in horseshoe crabs has been facilitated by the ease in collecting large volumes of blood and from the simplicity of the blood. Horseshoe crabs show only a single cell type in the general circulation, the granular amebocyte. The plasma has the salt content of sea water and only three abundant proteins, hemocyanin, the respiratory protein, the C-reactive proteins, which function in the cytolytic destruction of foreign cells, including bacterial cells, and &alpha;2-macroglobulin, which inhibits the proteases of invading pathogens. Blood is collected by direct cardiac puncture under conditions that minimize contamination by lipopolysaccharide (a.k.a., endotoxin, LPS), a product of the Gram-negative bacteria. A large animal can yield 200 - 400 mL of blood. For the study of the plasma, blood cells are immediately removed from the plasma by centrifugation and the plasma can then be fractionated into its constituent proteins. The blood cells are conveniently studied microscopically by collecting small volumes of blood into LPS-free isotonic saline (0.5 M NaCl) under conditions that permit direct microscopic examination by placing one of more LPS-free coverglasses on the culture dish surface, then mounting those coverglasses in simple observation chambers following cell attachment. A second preparation for direct observation is to collect 3 - 5 mL of blood in a LPS-free embryo dish and then explanting fragments of aggregated amebocytes to a chamber that sandwiches the tissue between a slide and a coverglass. In this preparation, the motile amebocytes migrate onto the coverglass surface, where they can readily be observed. The blood clotting system involves aggregation of amebocytes and the formation of an extracellular clot of a protein, coagulin, which is released from the secretory granules of the blood cells. Biochemical analysis of washed blood cells requires that aggregation and degranulation does not occur, which can be accomplished by collecting blood into 0.1 volumes of 2% Tween-20, 0.5 M LPS-free NaCl, followed by centrifugation of the cells and washing with 0.5 M NaCl.

The American horseshoe crab, Limulus polyphemus, is arguably the most convenient source for large quantities of blood of any invertebrate. The blood is simple in composition, with only one cell-type in the general circulation, the granular amebocyte, and only three abundant proteins in the plasma, hemocyanin, the C-reactive proteins, and &alpha;2-macroglobulin. Blood is collected from the heart and the blood cells and plasma are separated by centrifugation.

The horseshoe crab has the best-characterized immune system of any long-lived invertebrate.  The study of immunity in horseshoe crabs has been facilitated ...

Extraction of High Molecular Weight Genomic DNA from Soils and Sediments

The soil microbiome is a vast and relatively unexplored reservoir of genomic diversity and metabolic innovation that is intimately associated with nutrient and energy flow within terrestrial ecosystems. Cultivation-independent environmental genomic, also known as metagenomic, approaches promise unprecedented access to this genetic information with respect to pathway reconstruction and functional screening for high value therapeutic and biomass conversion processes. However, the soil microbiome still remains a challenge largely due to the difficulty in obtaining high molecular weight DNA of sufficient quality for large insert library production. Here we introduce a protocol for extracting high molecular weight, microbial community genomic DNA from soils and sediments. The quality of isolated genomic DNA is ideal for constructing large insert environmental genomic libraries for downstream sequencing and screening applications. 
The procedure starts with cell lysis. Cell walls and membranes of microbes are lysed by both mechanical (grinding) and chemical forces (&beta;-mercaptoethanol). Genomic DNA is then isolated using extraction buffer, chloroform-isoamyl alcohol and isopropyl alcohol. The buffers employed for the lysis and extraction steps include guanidine isothiocyanate and hexadecyltrimethylammonium bromide (CTAB) to preserve the integrity of the high molecular weight genomic DNA. Depending on your downstream application, the isolated genomic DNA can be further purified using cesium chloride (CsCl) gradient ultracentrifugation, which reduces impurities including humic acids. The first procedure, extraction, takes approximately 8 hours, excluding DNA quantification step. The CsCl gradient ultracentrifugation, is a two days process. During the entire procedure, genomic DNA should be treated gently to prevent shearing, avoid severe vortexing, and repetitive harsh pipetting.

A methodology to isolate high molecular weight and high quality genomic DNA from soil microbial community is described.

The soil microbiome is a vast and relatively unexplored reservoir of genomic diversity and metabolic innovation that is intimately associated with ...

Lipid Vesicle-mediated Affinity Chromatography using Magnetic Activated Cell Sorting (LIMACS): a Novel Method to Analyze Protein-lipid Interaction

The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification procedures. As an alternative, lipids can be coated on flat surfaces as used for lipid ELISA and Plasmon resonance spectroscopy. However, surface coating lipids do not form microdomain structures, which may be important for the lipid binding properties. Further, these methods do not allow for the purification of larger amounts of proteins binding to their target lipids.
 To overcome these limitations of testing lipid protein interaction and to purify lipid binding proteins we developed a novel method termed lipid vesicle-mediated affinity chromatography using magnetic-activated cell sorting (LIMACS). In this method, lipid vesicles are prepared with the target lipid and phosphatidylserine as the anchor lipid for Annexin V MACS. Phosphatidylserine is a ubiquitous cell membrane phospholipid that shows high affinity to the protein Annexin V. Using magnetic beads conjugated to Annexin V the phosphatidylserine-containing lipid vesicles will bind to the magnetic beads. When the lipid vesicles are incubated with a cell lysate the protein binding to the target lipid will also be bound to the beads and can be co-purified using MACS. This method can also be used to test if recombinant proteins reconstitute a protein complex binding to the target lipid. 
 We have used this method to show the interaction of atypical PKC (aPKC) with the sphingolipid ceramide and to co-purify prostate apoptosis response 4 (PAR-4), a protein binding to ceramide-associated aPKC. We have also used this method for the reconstitution of a ceramide-associated complex of recombinant aPKC with the cell polarity-related proteins Par6 and Cdc42. Since lipid vesicles can be prepared with a variety of sphingo- or phospholipids, LIMACS offers a versatile test for lipid-protein interaction in a lipid environment that resembles closely that of the cell membrane. Additional lipid protein complexes can be identified using proteomics analysis of lipid binding protein co-purified with the lipid vesicles.

Lipid Vesicle-mediated Affinity Chromatography using Magnetic Activated Cell Sorting LIMACS: a Novel Method to Analyze Protein-lipid Interaction

To test the interaction of a protein with its target lipid we used MACS and Annexin V-conjugated magnetic beads and lipid vesicles synthesized from the target lipid and Annexin V-binding phosphatidylserine. Proteins bound to the target lipid are co-purified and analyzed after elution from the beads.

The analysis of lipid protein interaction is difficult because lipids are embedded in cell membranes and therefore, inaccessible to most purification ...

Genomic MRI - a Public Resource for Studying Sequence Patterns within Genomic DNA

Non-coding genomic regions in complex eukaryotes, including intergenic areas, introns, and untranslated segments of exons, are profoundly non-random in their nucleotide composition and consist of a complex mosaic of sequence patterns. These patterns include so-called Mid-Range Inhomogeneity (MRI) regions -- sequences 30-10000 nucleotides in length that are enriched by a particular base or combination of bases (e.g. (G+T)-rich, purine-rich, etc.). MRI regions are associated with unusual (non-B-form) DNA structures that are often involved in regulation of gene expression, recombination, and other genetic processes (Fedorova &amp; Fedorov 2010). The existence of a strong fixation bias within MRI regions against mutations that tend to reduce their sequence inhomogeneity additionally supports the functionality and importance of these genomic sequences (Prakash et al. 2009).
Here we demonstrate a freely available Internet resource -- the Genomic MRI program package -- designed for computational analysis of genomic sequences in order to find and characterize various MRI patterns within them (Bechtel et al. 2008). This package also allows generation of randomized sequences with various properties and level of correspondence to the natural input DNA sequences. The main goal of this resource is to facilitate examination of vast regions of non-coding DNA that are still scarcely investigated and await thorough exploration and recognition.

We present a public computational web site for the analysis of genomic sequences. It detects DNA sequence patterns with various non-random nucleotide compositions. This resource also generates randomized sequences with diverse levels of complexity.

Non-coding genomic regions in complex eukaryotes, including intergenic areas, introns, and untranslated segments of exons, are profoundly non-random in ...

Selective Capture of 5-hydroxymethylcytosine from Genomic DNA

5-methylcytosine (5-mC) constitutes ~2-8% of the total cytosines in human genomic DNA and impacts a broad range of biological functions, including gene expression, maintenance of genome integrity, parental imprinting, X-chromosome inactivation, regulation of development, aging, and cancer1. Recently, the presence of an oxidized 5-mC, 5-hydroxymethylcytosine (5-hmC), was discovered in mammalian cells, in particular in embryonic stem (ES) cells and neuronal cells2-4. 5-hmC is generated by oxidation of 5-mC catalyzed by TET family iron (II)/&alpha;-ketoglutarate-dependent dioxygenases2, 3. 5-hmC is proposed to be involved in the maintenance of embryonic stem (mES) cell, normal hematopoiesis and malignancies, and zygote development2, 5-10. To better understand the function of 5-hmC, a reliable and straightforward sequencing system is essential. Traditional bisulfite sequencing cannot distinguish 5-hmC from 5-mC11. To unravel the biology of 5-hmC, we have developed a highly efficient and selective chemical approach to label and capture 5-hmC, taking advantage of a bacteriophage enzyme that adds a glucose moiety to 5-hmC specifically12.
Here we describe a straightforward two-step procedure for selective chemical labeling of 5-hmC. In the first labeling step, 5-hmC in genomic DNA is labeled with a 6-azide-glucose catalyzed by &beta;-GT, a glucosyltransferase from T4 bacteriophage, in a way that transfers the 6-azide-glucose to 5-hmC from the modified cofactor, UDP-6-N3-Glc (6-N3UDPG). In the second step, biotinylation, a disulfide biotin linker is attached to the azide group by click chemistry. Both steps are highly specific and efficient, leading to complete labeling regardless of the abundance of 5-hmC in genomic regions and giving extremely low background. Following biotinylation of 5-hmC, the 5-hmC-containing DNA fragments are then selectively captured using streptavidin beads in a density-independent manner. The resulting 5-hmC-enriched DNA fragments could be used for downstream analyses, including next-generation sequencing.
Our selective labeling and capture protocol confers high sensitivity, applicable to any source of genomic DNA with variable/diverse 5-hmC abundances. Although the main purpose of this protocol is its downstream application (i.e., next-generation sequencing to map out the 5-hmC distribution in genome), it is compatible with single-molecule, real-time SMRT (DNA) sequencing, which is capable of delivering single-base resolution sequencing of 5-hmC.

Described is a two-step labeling process using &beta;-glucosyltransferase (&beta;-GT) to transfer an azide-glucose to 5-hmC, followed by click chemistry to transfer a biotin linker for easy and density-independent enrichment. This efficient and specific labeling method enables enrichment of 5-hmC with extremely low background and high-throughput epigenomic mapping via next-generation sequencing.

5-methylcytosine (5-mC) constitutes ~2-8% of the total cytosines in human genomic DNA and impacts a broad range of biological functions, including gene ...

A Practical Guide to Phylogenetics for Nonexperts

Many researchers, across incredibly diverse foci, are applying phylogenetics to their research question(s). However, many researchers are new to this topic and so it presents inherent problems. Here we compile a practical introduction to phylogenetics for nonexperts.&#160;We outline in a step-by-step manner, a pipeline for generating reliable phylogenies from gene sequence datasets. We begin with a user-guide for similarity search tools via online interfaces as well as local executables. Next, we explore programs for generating multiple sequence alignments followed by protocols for using software to determine best-fit models of evolution. We then outline protocols for reconstructing phylogenetic relationships via maximum likelihood and Bayesian criteria&#160;and finally describe tools for visualizing phylogenetic trees. While this is not by any means an exhaustive description of phylogenetic approaches, it does provide the reader with practical starting information on key software applications commonly utilized by phylogeneticists. The vision for this article would be that it could serve as a practical training tool for researchers embarking on phylogenetic studies&#160;and also serve as an educational resource that could be incorporated into a classroom or teaching-lab.

Here we describe a step-by-step pipeline for generating reliable phylogenies from nucleotide or amino acid sequence datasets. This guide aims to serve researchers or students new to phylogenetic analysis.&#160;

Many researchers, across incredibly diverse foci, are applying phylogenetics to their research question(s). However, many researchers are new to this ...

A Method for Screening and Validation of Resistant Mutations Against Kinase Inhibitors

The discovery of BCR/ABL as a driver oncogene in chronic myeloid leukemia (CML) resulted in the development of Imatinib, which, in fact, demonstrated the potential of targeting the kinase in cancers by effectively treating the CML patients. This observation revolutionized drug development to target the oncogenic kinases implicated in various other malignancies, such as, EGFR, B-RAF, KIT and PDGFRs. However, one major drawback of anti-kinase therapies is the emergence of drug resistance mutations rendering the target to have reduced or lost affinity for the drug. Understanding the mechanisms employed by resistant variants not only helps in developing the next generation inhibitors but also gives impetus to clinical management using personalized medicine. We reported a retroviral vector based screening strategy to identify the spectrum of resistance conferring mutations in BCR/ABL, which has helped in developing the next generation BCR/ABL inhibitors. Using Ruxolitinib and JAK2 as a drug target pair, here we describe in vitro screening methods that utilizes the mouse BAF3 cells expressing the random mutation library of JAK2 kinase.

Emergence of genetic resistance against kinase inhibitor therapy poses significant challenge for effective cancer therapy. Identification and characterization of resistant mutations against a newly developed drug helps in better clinical management and next generation drug design. Here, we describe our protocol for in vitro screening and validation of resistant mutations.

The discovery of BCR/ABL as a driver oncogene in chronic myeloid leukemia (CML) resulted in the development of Imatinib, which, in fact, demonstrated the ...

Repeated Blood Collection for Blood Tests in Adult Zebrafish

Repeated blood collection is one of the most common techniques performed on laboratory animals. However, a non-lethal protocol for blood collection from zebrafish has not been established. The previous methods for blood collection from zebrafish are lethal, such as lateral incision, decapitation and tail ablation. Thus we have developed a novel &#8220;repeated&#8221; blood collection method, and present here a detailed protocol outlining this procedure. This method is minimally invasive and results in a very low mortality rate (2.3%) for zebrafish, thus enabling repeated blood sampling from the same individual. The maximum volume of blood sampling is dependent on body weight of the fish. The volume for repeated blood sampling at intervals should be&#160;&#8804;0.4% of body weight every week or &#8804;1% every 2 weeks, which were evaluated by measurements of blood hemoglobin. Additionally, hemoglobin, fasting blood glucose, plasma triacylglycerol (TG) and total cholesterol levels in male and female adult zebrafish were measured. We also applied this method to investigate the dysregulation of glucose metabolism in diet-induced obesity. This blood collection method will allow many applications, including glucose and lipid metabolism and hematological studies, which will increase the use of zebrafish as a human disease model organism.

Repeated blood sampling is necessary and important in animal research. We developed a novel, non-lethal and reliable method for repeated blood collection from adult zebrafish, and applied this method to the study of blood biochemistry, including glucose metabolism.

Repeated blood collection is one of the most common techniques performed on laboratory animals. However, a non-lethal protocol for blood collection from ...

Amplification, Next-generation Sequencing, and Genomic DNA Mapping of Retroviral Integration Sites

Retroviruses exhibit signature integration preferences on both the local and global scales. Here, we present a detailed protocol for (1) generation of diverse libraries of retroviral integration sites using ligation-mediated PCR (LM-PCR) amplification and next-generation sequencing (NGS), (2) mapping the genomic location of each virus-host junction using BEDTools, and (3) analyzing the data for statistical relevance. Genomic DNA extracted from infected cells is fragmented by digestion with restriction enzymes or by sonication. After suitable DNA end-repair, double-stranded linkers are ligated onto the DNA ends, and semi-nested PCR is conducted using primers complementary to both the long terminal repeat (LTR) end of the virus and the ligated linker DNA. The PCR primers carry sequences required for DNA clustering during NGS, negating the requirement for separate adapter ligation. Quality control (QC) is conducted to assess DNA fragment size distribution and adapter DNA incorporation prior to NGS. Sequence output files are filtered for LTR-containing reads, and the sequences defining the LTR and the linker are cropped away. Trimmed host cell sequences are mapped to a reference genome using BLAT and are filtered for minimally 97% identity to a unique point in the reference genome. Unique integration sites are scrutinized for adjacent nucleotide (nt) sequence and distribution relative to various genomic features. Using this protocol, integration site libraries of high complexity can be constructed from genomic DNA in three days. The entire protocol that encompasses exogenous viral infection of susceptible tissue culture cells to integration site analysis can therefore be conducted in approximately one to two weeks. Recent applications of this technology pertain to longitudinal analysis of integration sites from HIV-infected patients.

We describe a protocol for amplifying retroviral integration sites from the genomic DNA of infected cells, sequencing the amplified virus-host junctions, and then mapping these sequences to a reference genome. We also describe techniques to quantify the distribution of integration sites relative to various genomic annotations using BEDTools.

Retroviruses exhibit signature integration preferences on both the local and global scales. Here, we present a detailed protocol for (1) generation of ...