There are a number of ways to yield clean DNA from a high titer phage lysate. This one requires
about 1 mL of sample; PCI, a solution containing phenol, chlorophorm, and isoamyl alcohol (in a
25:24:1 ratio) will be used. Phenol is a hazardous material, causes skin burns, respiratory irritation,
headaches, and burning eyes. Wear gloves when handling PCI and work under the fume hood, PCI
is also light sensitive so make sure to wrap the container in foil and return it to the canister
immediately when done. Phenol is used to remove proteins and other contaminating materials
from aqueous DNA solutions. Chloroform helps to denature proteins as well as remove residual
phenol. Isoamyl alcohol is often added to the chloroform to reduce foaming. High salt molarity
(sodium acetate) increases aggregation of DNA and helps to precipitate it into a pellet. In this
alternative method, MgCl2 is used as a stabilizer.