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

- [Verteller] DNA-extractie is het verwijderen en zuiveren van DNA uit cellen.
 Ten eerste worden cellen gelyseerd, opengebroken, meestal door een combinatie van fysieke ontwrichting en behandeling met chemicali&#xEB;n, zoals detergenten, die de cel en de kernmembranen oplossen.
 De inhoud kan dan vrij door de omringende oplossing bewegen.
Vervolgens moet het DNA gescheiden worden van de andere aanwezige moleculen.
 Organische oplosmiddelen, zoals fenol en chloroform, worden vaak gebruikt om nucle&#xEF;nezuren van eiwitten te scheiden op basis van hun verschillende oplosbaarheid.
 Daarnaast kunnen prote&#xEF;nase en RNase enzymen worden gebruikt om eiwitten en RNA af te breken, waarbij het DNA intact blijft.
Zout wordt meestal toegevoegd aan het monster, dat de negatief geladen fosfaatgroepen in het skelet van het DNA stabiliseert en na de toevoeging van ijskoud alcohol, het DNA uit de oplossing doet bezinken.
 Het witte bezinksel wordt opgevangen door het te centrifugeren in een centrifuge, waar het zich op de bodem van de buis nestelt.
 Na het wassen en resuspenderen in een bufferoplossing kan het ge&#xEB;xtraheerde DNA uiteindelijk gebruikt worden voor onderzoek of biotechnologische toepassingen.

dna-isolatie

DNA Isolation

DNA uit cellen is nodig voor veel biotechnologie- en onderzoekstoepassingen, zoals moleculair klonen. Om DNA uit cellen te verwijderen en te zuiveren, gebruiken onderzoekers verschillende methoden voor DNA-extractie. Hoewel de specifieke kenmerken van verschillende protocollen kunnen vari&#xEB;ren, liggen enkele algemene concepten ten grondslag aan het proces van DNA-extractie.

<h4>THet proces</h4>

Eerst moeten cellen worden gelyseerd -opengebroken- om het DNA in oplossing te brengen. Cellen kunnen fysiek worden gelyseerd met behulp van apparatuur zoals een homogenisator, sonicator of kralenklopper, die maalt of anderszins kracht uitoefent om de cellen open te breken. Vaak worden tijdens de lyse stoffen zoals wasmiddelen toegevoegd om de op lipiden gebaseerde celmembranen chemisch te ontwrichten &#x2013; waardoor het DNA uit de kern en de cel wordt vrijgemaakt. Door het draaien in een centrifuge wordt het celafval naar de bodem gesedimenteerd en het lysaat &#x2013; dat cellulair materiaal bevat &#x2013; wordt verzameld voor verdere verwerking.

Het DNA moet dan gescheiden worden van andere cellulaire moleculen, zoals RNA en eiwitten. Daarom worden enzymen zoals RNase en Proteinase K vaak toegevoegd tijdens of na lyse om respectievelijk RNA en eiwitten af te breken. Bovendien worden organische oplosmiddelen zoals fenol en chloroform vaak gebruikt om DNA van eiwitten te scheiden. Typisch wordt het monster gewerveld met fenol-chloroform en vervolgens gecentrifugeerd om de waterige en organische fasen in de buis te scheiden. Vervolgens kan de DNA-houdende waterfase bovenaan worden afgepipetteerd, waarbij het eiwit in de organische fase achterblijft.

Zouten worden vaak toegevoegd tijdens DNA-extractie om het DNA te stabiliseren en te helpen het uit de oplossing te precipiteren. Een standaardmethode voor DNA-precipitatie is het toevoegen van ijskoude alcohol, zoals ethanol of isopropanol, aan het monster. Hierdoor vormt het DNA een wit, troebel buffers in de vloeistof in de buis.

Het monster wordt vervolgens in een centrifuge rondgedraaid, waardoor het DNA-precipitaat zich als een pellet op de bodem van de buis verzamelt. De pellet wordt gewassen door de vloeistof te verwijderen, in alcohol te wassen en opnieuw te centrifugeren. Na de laatste wasbeurt wordt de pellet opnieuw gesuspendeerd in een buffer-waardoor een waterige oplossing van gezuiverd DNA ontstaat die klaar is om te worden bestudeerd of gebruikt in de biotechnologie.

DNA-isolatie

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 isolation

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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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