The evaluation of antibacterial properties is performed according to the reference ISO standards according to the type of material, be it packaging or surfaces of various kinds.
The antibacterial activity can be tested using ATCC strains of Escherichia coli and Staphylococcus aureus (and other strains where appropriate). Bacterial suspensions of a known density are used to inoculate the surfaces under examination. After 24 hours of incubation at 37°C in a humid environment, viable bacterial cells are recovered using the recovery medium SCDLP (Soybean Casein Digest Lecithin Polysorbate 80 Medium). Scalar dilutions on base 10 of the recovered cells are inoculated by stab inoculation of Plate Count Agar and counted after 24 hours of incubation.
The amount of antibacterial activity (R) is calculated using the following algorithm:
R= (Ut-U0)-(At-U0)=Ut-At
where,
- R= abatement of antibacterial activity expressed in logarithm in base 10.
- U0= mean of the base 10 logarithm of the number of viable cells, in cells/cm2, recovered from the untreated sample immediately after inoculation.
- Ut= mean of the base 10 logarithm of the number of viable cells, in cells/cm2, recovered from the untreated sample 24 hours after inoculation.
- At= mean of the base 10 logarithm of the number of viable cells, in cells/cm2, recovered from the treated sample 24 hours after inoculation.
Services
- Test for evaluating the antibacterial properties, using an ATCC strain (Escherichia coli or Staphylococcus aureus)
- Test for evaluating the antibacterial properties, using two ATCC strains (Escherichia coli and Staphylococcus aureus, or other strains)
Rates
To receive the latest prices, please email the principal investigator, Dr. Monica Cricca.