Rationale: Filtered the flooded plate that has sat for 48 hours tot obtain a new lysate; conducted a plaque assay to calculate/test the titer strength.

Procedure:

• Created an aseptic zone to prevent/reduce bacterial contamination
• Obtained the previous flooded plate from the refrigerator
• Obtained a syringe filter (22μL) and filtered the PB into a 15mL conical vial
• Obtained a 50mL conical vial and added in 4mL LB Broth and 45μL CaCl2
• Added 20μL lysate to 0.5mL arthrobacter to infect
• Pipetted 5mL 2xTA into the conical vial and immediately added 4.5mL into the arthrobacter + lysate vial and plated
• Allowed plates to sit for 15 minutes and then incubated

Observations:

The new lysate obtained from filtering the PB of the flooded plate

The results of a plaque assay to observe the strength of the previous titer

10^-1 result of the previous titer

Next Steps/Conclusion: After performing this plaque assay, will be calculating the new titer strength and aiming to strengthen the titer strength. If the plate is negative / contaminated, will perform another plaque assay to check plaques and calculate the strength.