Test available for antimicrobials comprise of either a relatively quick qualitative test to establish whether antimicrobial function exists or a longer quantitative testing to quantify the effectiveness of the treatment.

If only bacteriostatic activity ( inhibition of multiplication) is intended, a qualitative test is acceptable
However, if bacteriocidal activity ( destruction of the bacteria) is intended or implied, quantitative evaluation is necessary.

Kirby Bauer Method

in a sterile petri dish the agar surface is completely swapped with a bacterial solution, the sample is placed in the center and incubated @ body temperature for 48hrs diffusable antibacterial agents will show a zone of inhibition

AATCC 147 Parallel Streak Method

the bacterial solution is transferred to the surface of a sterile agar plate by making five streaks in the center of the plate; the sample is place transversely across the five streaks; plates are incubated at body temperature for 48hrs.

AATCC 100 Assessment of Antibacterial Finishes on Textile Materials

Test and control swatches are inoculated with the test organisms. After 24h incubation the bacteria are eluted from the swatches by shaking in known amounts of neutralizing solution. The number of bacteria present in this liquid is determined and the percentage reduction of the treated specimen is calculated.

In the absence of a control swatch the number of bacteria is determined between samples incubated at 0 hrs and 24 hrs.