Rationale: In order to move to DNA extraction, 10 mL of lysate of pure DNA is needed. Due to a shortage of lysate, plaque assays were created in order to flood and obtain the lysate of pure DNA.

Procedure:

• After contamination prevention measures were taken, 125 microliters of lysate was added to 0.5 mL of Arthrobacter and allowed for infection for 10 minutes.
• In another test tube, 2.0 mL of LB broth and 22.5 microliters of calcium chloride were added together.
• After the 10 minutes, the lysate and Arthrobacter was added to the LB Broth and calcium chloride.
• Then, 2.5 mL of 1X Top Agar was added to each test tube then quickly added to the plate. To solidify, the plate was left alone for 15 minutes.

Results and Analysis:

First Phage

Head: 52 nm

Tail: 180 nm

Second Phage

Head: 47 nm

Tail: 106 nm

Conclusion:

Due to the inability to reach the minimum amount of lysate needed for DNA extraction, plaque assays were made to be used for flooding. In order to do this, plaque assays were made using 125 microliters of lysate was added with 5 mL of Arthrobacter then left alone to infect. For the culture, LB broth and calcium chloride were combined together. Then, the infected Arthrobacter was added to the culture. After, the top agar was added then plated.

Future Plans:

If phages are present, the titer will be calculated and will be used to determine if it is a high titer. If there are no phages present, plaque assays will be done again.