Rationale:

Went back to the most recent plaque assay (Made on 10/1) and picked a plaque to create another plaque assay since the one conducted on 10/3 was contaminated.

Procedure:

• Created an aseptic zone to prevent the possible contamination of the plate / lab from bacteria
• Obtained the 10/1 plaque assay from the freezer
• Prepared a microcentrifuge vial with 100μL PB
• Picked a plaque from the plaque assay and pipetted into the vial (This is the 10^0)
• Obtained a 50 mL conical vial and added in 4mL LB Broth and 45 mL CaCl2 (Enough for two plates)
• Took the 10^0 and added 10μL into 0.5mL Arthrobacter and allowed to sit for 15 minutes
• Added 5mL 2X TA into the conical vial, and immediately transferred 4.5mL to the arthrobacter+lysate vial and plated
• The plates were allowed to sit for 15 minutes and then incubated

Observations:

The contaminated TA control plate

The contaminated 10/3 10^0 plate with no plaques visible

The 10/1 plaque assay with the plaque I picked circled

Next Steps/Conclusion:

After this plaque assay, will be calculating the titer of the plate and calculating how much of the titer would be needed to web a plate. If there is contamination, then the plaque assay step will be repeated