Rationale: Due to the plaque assay from last week turning up incorrectly formed I have to reconduct my plaque assay.

Procedure:

1. Pipetted 10μL of lysate into 0.5mL of arthrobacter. Then waited for 10minutes before beginning to make top agar.
2. Using aseptic technique and fresh pipettes each time put 8mL of LBbroth in a 50mL tube, then 90μL of CaCl2, then 10mL of 2X TA.
3. Pipetted 4.5mL into negative control plate.
4. Pipetted 4.5mL into tube with arthrobacter and lysate and pipetted up anddown to mix.
5. Poured contents into plate while keeping the top as close to the bottom aspossible as to not have any contaminants fall in.
6. Waited 10 minutes to solidify then inverted and incubated for 48 hours.

Observations: Control was completely clear however the test plate had an unusual web-like pattern similar to the image on the right. I accidentally threw my plate away before taking a picture, but my plate looked nearly identical to the plate of my lab partner so it is being shown below.

Interpretations and Next Steps: Since this is the second time the plate turned out with an unreadable result we will run an arthro+phage buffer control next time to make sure that the arthro is growing properly and that the phage doesn’t just look like this.