Objective:

• Wash the soil sample (Soil B) to remove unnecessary material, such as dirt, rocks, and bacteria.
• Isolate possible bacteriophage found in the soil, in lysate.
• Collect metadata on soil sample “Soil B” to obtain more information about the environment the soil was collected in and have further data on the preferred environment of Arthrobacter phage.

Procedure:

Washing=

1. Aseptic Zone was prepared. Lab space was cleaned using CiDeon and wiped dry with paper towel. Ethanol (70%) was then sprayed, wiped, and evaporated. Ethanol burner was then lit on the table.
2. 15 mL tube was obtained and filled to 2 mL with Soil B and filled to 12 mL with LB broth.
3. The tube was hand shaken for 15 minutes to mix the soil and broth.
4. The tube was then massed (21.82 g) and centrifuged @ 10,000 g for 5 minutes.
5. After the centrifuge, the liquid found at the top of the soil in the tube was then filtered using a top filter and vacuum. This was to remove the bacteria from the remaining soil. 10 mL of filtrate was obtained from the filter in a 50 mL tube.
6. 0.5 mL of Arthrobacter was added to the lysate (10 mL) in the 50 mL tube. This created the enriched lysate.
7. The 50 mL tube was then placed in the fridge until the next lab (9/12).

Metadata=

1. To find the percent water present in Soil B, a clean petri dish was obtain and massed. It was measured to be 7.19 g.
2. Then 4.03 g of Soil B was placed on the plate and left to dry out for 48 hours. Together, the soil and plate had a mass of 11.22 g. This total was recorded as the “wet soil” data.
3. The pH of the soil was also measured. Using a small vial, small amount of soil, and DI water, the mixture was shaken for 30 seconds. The vial was left to sit for 2 minutes to settle.
4. After settling, pH testing paper was placed in the vial for 5 seconds and the pH paper strip was compared to a pH key. It was determined that the pH of Soil B was 6.5.

Results:

• Since Soil B was a new sample being tested, there are no results to report from previous testing. Results from the “wet soil” metadata will be available in next lab (9/12).

Next Steps:

• In the next lab, a plaque assay will be completed using the enriched lysate that was made today. Additional metadata will also be collected, including the amounts of sand, silt, and clay present in the soil sample.