Rationale: Due the arthrobacter being contaminated Monday based off of the positive control we will have to reconduct the plaque assay.

Procedure:

1. Pipetted 10μL of lysate into 0.4mL of arthrobacter. Only used 0.4mL ofarthrobacter because not enough due to contamination of supply. Then

   waited for 10 minutes before beginning to make top agar.

2. Using aseptic technique and fresh pipettes each time put 8.4mL of LB brothin a 50mL tube, then 90μL of CaCl2, then 10mL of 2X TA.
3. Found a contaminant in TA supply so threw out the top agar we made andisolated the 2X TA from the other bottles.
4. Grabbed a new bottle of TA and labeled Group 2 and began making a newbatch of top agar using the same procedure as #2.
5. Pipetted 4.5mL into tube with arthrobacter and lysate and pipetted up anddown to mix.
6. Poured contents into plate while keeping the top as close to the bottom aspossible as to not have any contaminants fall in.
7. Waited 10 minutes to solidify then inverted and incubated for 48 hours.

Observations:
Another negative plaque assay. Was angry so accidentally threw in trash before taking picture. On the bright side at least the control was clear.

Interpretations and Next Steps: Going forward we need to be more diligent about keeping lid of the plate open for as short a time as possible. Also, now that we have found a contaminant in the TA we need to check the TA against the light before putting in the tube. We should also be more careful about the sterile pipette coming in contact with anything then putting it in the supply of anything whether it be LB broth or TA.