UW-Stout/UV Light SP21

Materials

• Cell 60 mm Culture Dish, containing 6 ml of agar
• Phosphate Buffered Saline (PBS)
• Glycerol stocks of yeast strains
• 15ml centrifuge tubes

Equipment

• Incubator set to 30°C.
• Bachur & Associates Sanata Clara, CA 95050 Model LS-100-3 UV Light Exposeure System
• P1000 and P10 Micro-pipettes

Calibration Protocol

1. Fill a 15ml centrifuge tube with 9,990ul of PBS.
2. Vortex yeast stock to resuspend the yeast cells.
3. Pipette 10ul of wild yeast stock into the 9,990ul of PBS to create a dilution containing 2 yeast cells per microliter.
4. Vortex dilution and prepare 7 plates with 50ul of the wild yeast dilution for about 100 yeast cells per plate.
5. Label each plate individually 0, 500, 600, 700, 800, 900 and 1000 for the number of seconds each plate will be exposed to the UV light.
6. Set up the UV light exposure system:
   1. 400 watts
   2. desired time increment
7. Run yeast plates (without plate top) under the UV light for their respective times in seconds.
8. Place plates upside down in dark incubator set to 30°C for 48 hours.
9. Count number of colonies on each plate using the 0 second plate as your control to compare to. Based on how many colonies there are on each plate, determine the time frame that killed roughly 50% of the yeast cells.

Calibration Results