DNA Extraction FAQ. What Are DNA Extraction Techniques? Plus Other DNA Extraction Questions

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What is DNA Extraction?

DNA can be extracted from a number of different types of cells for many different reasons. DNA extraction refers to the methods of removing genetic material from cells for study and analysis. It’s an important and valuable technology and below are some of the frequently asked questions about DNA extractions. This article is ideal for those starting out on the exciting DNA learning adventure.

Why is DNA Extracted From Cells?

There are many reasons why a scientist might want to extract DNA from a cell, be it a human cell, plant cell, bacterial or viral cell.

Human Cells

  1. Genetic testing - to detect disease risk or determine ancestry

  2. To identify a body

  3. To help forensic scientists investigating a crime scene.

DNA extraction can also be used to detect bacterial and viral particles in the environment, or to study plants and fungi, and to determine phylogeny.

Where is DNA Extracted From?

DNA can be extracted from a number of different sources and plant DNA extraction and bacterial DNA extraction are common. Other sources include …

… in fact any cell that harbours DNA can, with suitable methods, have its DNA extracted.

What are DNA Extraction Techniques?

There are several fundamental steps involved in extracting DNA from cells.

  1. Cells have to be isolated
  1. DNA has to be isolated and purified so cells are lysed (burst open) to gain access to the nuclear DNA. This can be achieved by a number of methods including grinding or sonication (ultrasound). Detergent may be used to remove lipid membranes. Protease enzymes are used to strip proteins away from the DNA.

  2. DNA is then precipitated by mixing with an alcohol and then centrifuging.

What Equipment is Used to Extract DNA?

Instruments used to extract DNA from a cell include;

A bead beater - to break open or lyse the cell

Centrifuge - to precipitate the DNA

A gel box - used to separate DNA in an agarose gel with the application of an electric charge.