Team:BYU Provo/Notebook/Phage Purification/Winterexp/Period1/Exp/5.26 PEG Purification

Overview

March-April

May-June

July-August

September-October

The first step in the phage purification process. Purify phage from bacterial debris.

II) Expected Outcome

Phage will be purified from the bacterial debris to be further purified in a CsCl gradient.

III) Reagants Used

phage suspension buffer

10 mM Tris-HCl

100 mM NaCl

10 mM MgCl₂

DNase I

RNase A

chloroform

NaCl powder

PEG 8000

T4 and T7 bacterial lysate

IV) Actual Procedure

Add 185 microL DNase and 25 microL RNase to T4 and T7 bacterial lysates.

Add .1 mL chloroform to complete lysis and let the preparations sit for 30 minutes at room temperature.

Dissolve 1.465 g of solid NaCl and let cool at 4^◦ C for 1 hour.

Centrifuge the suspensions at 6500 rpms (7000 g) for 10 minutes at 4^◦ C. Remove supernatant and put in clean flasks.

Dissolve 4.05 mg PEG 8000 and let sit at 4^◦ C for 1 hour.

Centrifuge the suspensions at 8000 rpms (10000 g) for 15 minutes at 4^◦ C. Discard the supernatant.

Turn the centrifuge bottles over to let sit for 5 minutes to drain off any remaining supernatant.

Suspend the pellets in .675 mL phage suspension buffer and let sit overnight at 4^◦ C.

V) Results

After centrifugation, we were able to see a distinct band of phage in both the T4 and T7 gradients. The T7 band was significantly lower in the tube than the T4 band. Next time we run the procedure, we will be running the T7 phage through a higher concentrated gradient. After leaving the gradients overnight in the refrigerator, the gradients mixed together and we were unable to see the distinct bands to extract the phage. We will have to rerun the experiment.