Optical Density (OD) Readings

Optical Density

Flow Chart

If not able to read OD above a low level:

  • Standardize LED/Photodiode distance

If seeing noisy OD readings:

  • Stirring

If OD is not working at all on a single vial: Replacing Photodiodes and LEDs


Experiment Considerations

  • Photodiode Temperature - make sure temperature is equilibrated before calibration and before start of experiment

  • eVOLVER recently turned on - causes rapid change in values

  • Needles or other structures coming below 10mL line (close to OD PD etc)

  • Vial volume - a volume of 10mL will totally change OD compared to 30

  • Stirring with low vial volume - this will give noisy readings as the funnel created by stirring fluctuates and is more and less reflective

Pre-Calibration Considerations

Non-standard changes

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