Rationale:

The purpose of today’s lab was to continue with the purification and amplification process to gather consistent phage particles.

Results from 10/10/18:

• Top Agar had split, not allowing for the proper formation of plaques. Meaning the top agar had not fully solidified before being flipped and inserted into the incubator. Plaque assays had to be redone.
• 

Materials:

• LB Broth
• 2X TA
• Diluted Lysates
• Agar Plates

Procedure:

1. Established an aseptic zone.
2. Mass of dry plate was recorded from water percentage experiment.
3. Once diluted, 3 separate plaque assays were run with each dilution.
4. 2.0-mL of LB broth was added into 3 separate conical vials.
5. Next, 22.5-μL of calcium chloride was added to the each of the conical vials.
6. 10-μL of each of the dilutions was combined with 3 separate 500-mL quantities of Arthrobacter and left to infect.
7. After about 15 minutes, the diluted lysates were combined with their LB Broth mixtures and 2.5-mL of 2X TA was added to the broths.
8. Swirled and plated top agars immediately.
9. Once solidified, they were flipped and added to the incubator until the next lab.

Results/Data:

• The top agar seemed solidified before inserted into the incubator with no clear indicator splitting.
• The mass of the dry soil with plate 3.49 g, making the mass of the dry soil 1.53 g.
• The mass of the water was 1.93- 1.53 = 0.4 grams
• Water percentage = 20.7%

Conclusions:

The water percent of the soil sample was relatively low, which is unsurprising due to the relative dryness of the soil once it was collected. Soil was not extremely clay like, and was very pebbly.

Next Steps:

The next steps for this experiment are to analyze the plaque assay results for phage particles. If there are no plaques present, new plaques and dilutions will be performed to test through plaque assays again.