Time-Kill Kinetics Test – Antimicrobial Efficacy Testing

Time-Kill Kinetics test also known as the “suspension tests or suspension time kill analysis” determines the time required by the antimicrobial agent to kill the challenge test microorganism.

Principle and Basis of the Time-Kill Kinetics

The Time Kill Test is used in microbiology to assess a test object’s in vitro antimicrobial activity in relation to time. When clients request our services, essentially our scientists will follow the procedure described below:  the undiluted and/or diluted test compound is introduced to a particular test bacteria at time zero. This mixture is grown at a set temperature and time intervals, samples are taken out, put into a neutralization buffer, and then the  microbe population is enumerated. The resulting data for the Time Kill test is typically presented graphically, where the colony counts for each antimicrobial agent is plotted against the concentration tested at each time point at which subcultures were performed (usually at 0, 4, 8, 12, and 24 hours). Generally, in a Time Kill Test, a 3 Log10 reduction is considered the minimum level that would indicate a product has significant killing activity against a particular test microorganism, while, as in the minimal bactericidal concentration (MBC) test, bactericidal activity is defined as a 99.9% or greater killing efficacy at a specified time.

Emery Pharma has successfully performed a number of Time Kill testing for multiple clients in pharmaceutical industry following the guidelines set by the Clinical & Laboratory Standards Institute (CLSI)

Time Kill Kinetic Assay Log Reduction

Time-kill Kinetics as a Log reduction with a test compound (CFU/mL) at 1 minute and 5 minutes.