Fill in the roles for the DNA extraction procedure:

a) Caused DNA to aggregate and precipitate out of the extract so you can see it. ____________________

b) Added positively charged ions that attract to the negatively charged phosphates of DNA making it less soluble in water. ________________________

c) Source of DNA molecules. ___________________ 

d) Removed the plasma membrane and nuclear membrane. _________________________

e) Digests the histone proteins to free pure DNA in the extract solution. ___________________________