Rationale

Today we will conduct another plaque assay with soil sample #3. Lucy’s plaque assay results were positive while Sona’s and I were not, despite the soil originating from the same point in the tree; therefore we will test our soil again to confirm the results.

Procedure

• Established an aseptic zone.
• 8 mL of LB broth and 90 µL of CaCl2 were added to a vial.
• 10 µL of enriched lysate was added to a vial containing 0.5 mL of Arthrobacter. It sat for 10 minutes.
• 10 mL of 2X TA was added to the first tube and 4.5 mL of the solution was added to the vial containing the enriched lysate and 0.5 mL of Arthrobacter. The contents of the mixture were then poured onto a plate and sat for 10 minutes.

Observation

When the contents of the mixture were poured onto the plate, no air bubbles were formed.

Conclusion/Next Steps

The results of the plaque assay will be observed on 10/3/18. If negative, we will collect another soil sample.