Date: Monday, October 15th, 2018

Title: Plaque Assay for Soil Sample C

Rationale: The purpose of today’s lab is to make a plaque assay for a new soil sample in order to search for plaques.

Class Question: Is there a difference in bacteriophage presence or type in soil samples taken from live oaks vs those from red oaks?

Procedure:

1. An aseptic zone was set up
2. Enriched lysate was retrieved from the incubator.
3. 10 microliters of enriched lysate was added to a culture tube with .5 mL arthrobacter and left to sit for 15 minutes.
4. Agar was made for three plates with the following formula:
   1. 6 mL LB broth
   2. 7.5 mL 2x TA
   3. 67.5 microliters 1M CaCl2
5. 4.5 mL of the TA solution was added to each culture tube and the TA control plate.
6. The plates were left for 20 minutes to harden before being inverted and incubated for the next 48 hours.

Observations: One of the group members, Lucy Fisher, had a pink coloration to her enriched lysate. There has been a red bacteria travelling around the lab and has grown on some students’ plates.

Results: This experiment yielded a plaque assay that can be evaluated at a later date for plaques.

Next Steps: The next step is to evaluate the plaque assay. If it yields positive results, the next step is to pick a plaque. If negative, a new sample may have to be adopted.