DNA Isolation from Plant Tissue - Answer Key
After reading the procedure and performing the DNA extraction, answer the following questions.
1. What is the purpose of the following equipment or compounds:
2. Explain how the differences in polarity of the solvents (salt-water-CTAB solution, chloroform, isopropyl alcohol) allow this procedure to work.
The charged DNA molecules are initially dissolved
in the polar salt-water CTAB solution. When this solution is mixed with chloroform,
the nonpolar compounds in the mixture dissolved into the chloroform layer, away
from the aqueous DNA layer. Last, when the weakly polar isopropyl alcohol is
added to the aqueous solution, the large, negatively charged DNA molecules are
no longer soluble in the solution, and they precipitate out as visible strands.
3. Given that animal cells don't have cell walls or as many polysaccharides in them, what might you do differently to isolate DNA from animal cells.
You wouldn't need to grind them in a grinder.
A detergent is enough to break up the lipid plasma membrane.