Rationale: To perform another plaque assay for soil sample C, since the last plaque assay plates showed signs of contamination and resulted in negative plates.  

Procedure: 

1. Cleaned the lab table with Cidecon and 70% ethanol, and created an aseptic zone using an ethanol burner.  
2. Obtained enriched lysate for soil sample C ,50 mL tube, and 0.5 mL of Arthro.  
3. Pipetted 10 uL of enriched lysate into 0.5 mL Arthro, and let it sit for 10 minutes. 
4. Added 8 mL of LB Broth into 50 mL tube.  
5. Added 90 uL of CaCl2 
6. After 10 minutes were up, added 10 mL of Top Agar into the 50 mL tube.  
7. Pipetted 4.5 mL of Top Agar into tube containing lysate and Arthro. 
8. Poured rest of tube into control plate.  
9. Let the plates sit for 10 minutes.  
10. Stored the plates upright since the plates were sliding.  

Observations/ Results: 

Last plaque assay: 

The Control plate was contaminated, and therefore my plate had negative results.  

Contaminated Control Plate

negative individual plate + some contamination

Plaque assay plated today: 

Noticed that the control plate and my plate was sliding and didn’t set, possibly to the fact that we took a longer time to plate. There were a couple of bubbles in the corner while we poured the my individual solution into the plate.

Next Steps: 

We will observe the results of this plaque assay. If the plaque assay is positive and plaques are present then we will pick the plaques, amplify the plaques, and perform more plaque assays. If the plate comes out negative, we will collect soil, start on the soil metadata, and create an enriched lysate for the new soil solution.