Next, a buffered salt water solution is added into which DNA dissolves easily. The DNA is purified by adding an organic solution into which other molecules, such as fats and proteins dissolve. The purified DNA solution is separated off and the DNA is precipitated out of the solution by adding alcohol. The DNA is now a solid string that can be spooled out with a hook. The extracted DNA is placed into test tubes with a weak buffer solution and can be stored almost indefinitely. During DNA extractions, the entire cells' DNA is extracted at the same time. Extracted DNA has usually been sheared into smaller pieces due to the leaf tissue grinding process. This makes it difficult to isolate an entire chromosome in once continuous strand. However, large pieces that contain several to dozens of genes can be extracted intact with this method. After isolating the DNA, researchers can use it for further laboratory studies including genetic engineering. |
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