1.1 ,This practice specifies the parameters for growing a Pseudomonas aeruginosa (ATCC 15442) or Staphylococcus aureus (ATCC 6538) biofilm that can be used for disinfectant efficacy testing using the Test Method for Evaluating Disinfectant Efficacy Against Pseudomonas aeruginosa Biofilm Grown in CDC Biofilm Reactor Using Single Tube Method (E2871) or in an alternate method capable of accommodating the coupons used in the CDC Biofilm Reactor. The resulting biofilm is representative of generalized situations where biofilm exist on hard, non-porous surfaces under shear rather than being representative of one particular environment. Additional bacteria may be grown using the basic procedure outlined in this document, however, alternative preparation procedures for frozen stock cultures and biofilm generation (for example, medium concentrations, baffle speed, temperature, incubation times, coupon types, etc.) may be necessary.