Final answer:
Proteases and RNAses are used to inactivate proteins and RNA during DNA extraction, protecting the DNA from degradation. Ethanol precipitates the DNA for collection.
Step-by-step explanation:
The component of the lab that prevents DNA from being degraded as it is extracted is generally a combination of chemicals and enzymes. During the extraction process, cells are lysed using a detergent solution and the cell debris is separated by centrifugation. To preserve the DNA, enzymatic reactions are employed to destroy all undesired macromolecules.
Proteases are used to inactivate proteins and ribonucleases (RNAses) are used to break down RNA, which can contaminate or degrade DNA. Finally, the DNA is precipitated out of solution using ethanol, resulting in a gelatinous, white mass that can be spooled on a rod or stored at ultra-low temperatures for long-term preservation.