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ASTM E2149 – Standard Test Method for Determining the Antimicrobial Activity of Antimicrobial Agents Under Dynamic Contact Conditions


Purpose and Goals

  • Evaluate and compare the antimicrobial activity of multiple textiles against a variety of microbes at different contact times in laboratory-controlled testing. 

Materials and Methods

  • The testing will be performed according to / as a modification to ASTM’s Standard Test Method E2149-20. 
  • Textile/Paper/Powder/Granule samples (1.0 g each) will be placed into a sterile flask with a large volume of liquid microbial suspension and shaken for the specified contact times at room temperature. After exposure, the remaining live microbes from each sample’s liquid solution will be decanted or filtered as needed to remove the powder/granular sample and then dilution-plated onto nutrient agar to provide quantifiable viable microbial burden data for each sample tested. 
  • Each test’s microbial inoculum solution will contain a wetting agent: Triton X-100 (0.01%) to maximize the interaction between the sample’s antimicrobial agent and the test strain. 
  • Each test will include one of two bacterial strains:
    • Escherichia coli​ (ATCC 25922) – bacteria
    • Staphylococcus aureus (ATCC 6538) – the standard bacteria 
    • Klebsiella pneumoniae (ATCC 4352) – the standard bacteria 
    • Methicillin-resistant ​Staphylococcus aureus​ (MRSA) (ATCC 33591) bacteria
    • Carbapenem-resistant Klebsiella pneumoniae (KPC) (ATCC BAA-1705) bacteria
  • Testing will include 24 total data points per microbial strain:
    • 2 materials (1 test textiles and 1 in-house negative control)
      • Note: Please provide at least 10 grams of each material per time-point. 
    • 2 time-points (0 and 1 hour)
    • 3 replicates per sample at each test condition per test
    • 2 independent tests
  • Note: Optional Leach testing can be included for an additional fee.
  • Note: Optional GLP services are available for an additional fee.
  • Note: Bulk discounts are available for 4+ samples.
  • Note: Sterilization of materials before testing is NOT recommended due to possible deterioration and only performed by autoclaving upon request.

Data Analysis

  • In-house control results will be used to verify test validity. 
  • Data will be calculated to determine the quantifiable microbial burden remaining on each test sample.
  • Data will be analyzed to determine the consistency between replicate samples in each set (n=6).
  • Data will be analyzed to determine the percent reductions and log reductions of microbial burdens on each test material compared to negative control at each test condition.