Final answer:
In DNA purification, after centrifugation, cell debris becomes a pellet at the bottom of the tube, the supernatant with DNA is transferred to a new tube, and DNA is then precipitated with ethanol.
Step-by-step explanation:
During DNA purification, after the cell contents are treated with protease and RNAase, and the mixture is shaken and centrifuged, the cell debris will be pelleted at the bottom of the tube. The supernatant, which contains the DNA, is then carefully transferred to a clean tube avoiding the pellet.
Lastly, DNA is precipitated with ethanol, forming viscous strands that can subsequently be spooled on a glass rod to fully separate it from other substances.
After shaking the tube during DNA purification, the DNA will be trapped in different parts of the purification process. One instance is when the cell debris is pelleted in a centrifuge, and the supernatant containing the DNA is transferred to a clean tube. Another instance is when the DNA is precipitated with ethanol, forming viscous strands that can be spooled on a glass rod.