The Microstar Lab

Bacterial Test - Other Bacterial Testing Methods


Standard Practice for Determining Resistance of Plastics to Bacteria. The standard was withdrawn in 2002 but can still be performed. The standard is comprised of two different procedures.
  • In Procedure A, test pieces are placed on the surface of a nutrient-salts agar that has been inoculated with test organism. The test is then incubated and examined for visual effects after 21 days.
  • In Procedure B, a test piece is placed onto the surface of the seeded nutrient-salts agar. Then more of the seeded agar is placed on top of sample to completely cover it with the inoculated agar. The samples are then incubated as done in Procedure A.
  • The test organism is Pseudomonas aeruginosa ATCC #13388.
  • Samples are evaluated for visual effects only. Section 10.2 in the test method, Effect on Physical, Optical, or Electrical Properties, is not performed.


Resistance of Vinyls to Mildew (“Pink” Staining)

This method is used to determine the resistance of vinyl to mildew growth which may cause a “pink” staining condition in the field. Samples are tested against Streptomyces rubrireticuli and observed for the degree of staining on the samples as compared to a control.

GM 9303P

Mildew Resistance – Pink Stain for Plastics

In this test, samples are placed onto an agar plate that has been seeded with the bacterium, Streptoverticillium reticulum and allowed to incubate for 14 days. Samples are evaluated for staining from the pink bacterium and also for any zone of inhibition.