Name: steps in dna extraction
Uploaded: 2026-08-26T08:20:38.799Z
Duration: 1 min 58 s
Channel: JoVE

DNA extraction is the removal and purification of DNA from cells. First cells are lysed, broken open. Usually through a combination of physical disruption and treatment with chemicals such as detergent which dissolves the cell and nuclear membranes. The content can then float freely into the surrounding solution.

Next DNA must be separated from the other molecules present. Organic solvents such as phenol and chloroform are commonly used to separate nucleic acids from proteins based on their differing solubility.Additionally, proteinase and RNase enzymes can be used to degrade proteins and RNA leaving the DNA intact.

Salt is usually added to the sample which stabilizes the negatively charged phosphate groups in the backbone of the DNA. And after the addition of ice cold alcohol, precipitates the DNA out of the solution.&#xA0;

The white precipitate is collected by spinning it in a centrifuge where it settles to the bottom of the tube. After washing and re-suspending it in a buffer solution, the extracted DNA can finally be used in research or biotechnology applications.

dna分离

DNA Isolation

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DNA分离

DNA from cells is required for many biotechnology and research applications, such as molecular cloning. To remove and purify DNA from cells, researchers ...

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steps in dna extraction

DNA extraction is the process of removing and purifying DNA from cells. It is used in many biotechnology and research applications, including molecular cloning. The main goal is to free DNA from the cell and prepare it for later study or use.

The first step is cell lysis, which means breaking cells open. Researchers may use a homogenizer, sonicator, or bead beater to physically lyse the cells. They also often add detergent to chemically disrupt the lipid-based cell membranes. This helps release DNA from the nucleus and the rest of the cell.

After lysis, the sample is spun in a centrifuge. This causes cell debris to settle at the bottom, while the liquid lysate is kept for the next steps. The DNA then has to be separated from other cellular molecules, such as RNA and proteins. Enzymes like RNase and Proteinase K are often added to break down RNA and proteins, and phenol-chloroform can be used to separate DNA from protein.

During the phenol-chloroform step, the sample is vortexed and centrifuged again. The tube separates into an aqueous phase and an organic phase. The DNA stays in the aqueous phase at the top, and this layer can be pipetted off. Salts are often added to help stabilize the DNA and support precipitation.

To collect the DNA, ice-cold alcohol such as ethanol or isopropanol is added. The DNA then forms a white, cloudy precipitate in the tube. Another centrifuge spin pulls this DNA into a pellet at the bottom. The pellet is washed with alcohol, spun again, and then re-suspended in buffer to make a purified DNA solution ready for biotechnology work.

Steps in DNA Extraction

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DNA extraction is the process of removing and purifying DNA from cells. It is used in many biotechnology and research applications, including molecular cloning. The main goal is to free DNA from the cell and prepare it for later study or use. The first step is cell lysis, which means breaking cells open. Researchers may use a homogenizer, sonicator, or bead beater to physically lyse the cells. They also often add detergent to chemically disrupt the lipid-based cell membranes. This helps...

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in-vitro mutagenesis (gene knockouts)

Knockout Mice and Gene Replacement

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crispr

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gene therapy

Gene Delivery for Serious Diseases

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Cloning Animals with SCNT

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genomics

Genomics and DNA Sequencing

Genomics studies the full set of genetic material in an organism. In humans, that genome includes the DNA carried in 23 pairs of chromosomes in the nucleus, along with mitochondrial DNA. Genomics looks at both coding DNA and non-coding DNA, which helps scientists study how living things are built and how they differ. This field is useful in many areas of biology and medicine. Scientists use genomics to build phylogenetic trees, improve crop productivity and sustainability, help with criminal...

key terms and concepts

Learn the main steps in DNA extraction, including cell lysis, centrifugation, protein removal, and DNA precipitation for purified samples.

Steps in DNA Extraction | JoVE K12

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Steps in DNA Extraction

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