Validation Approach


Our validation approach

Growth Direct™ performs automated cassette incubation and colony enumeration and reporting using a media cassette, which contains a growth media that shows viability of microbial cells through growth, as required in the Pharmacopeia.

  • For environmental monitoring, the only consumable difference is the presence of a membrane on the media surface 
  • For water/bioburden testing, the consumables are equivalent to the standard method

The performance testing of Growth Direct consumables is identical to standard media plates, as defined in the US Pharmacopeia Ch<1223> and European Pharmacopeia microbiology chapters 5.1.6. The key system components to validate are:

  • The two incubators on the system (calibration and mapping)
  • The optical enumeration system and the electronic data transfer (if used)

As an automated colony counter, the validation requirement as defined in the PDA Technical Report 33 (TR33) will only be the accuracy and precision of the system compared to the reference standard, which is the analyst count. These two requirements are the same as for the validation of standard microbiology methods when spike and recovery experiments are performed. Precision is required to provide good estimates of colony forming units (CFUs) to compare to the control inoculation to determine accuracy.

This validation approach has been proven in use at many pharmaceutical sites that have received regulatory approval to perform environmental monitoring, water testing, and bioburden testing with Growth Direct.