Unlike conventional susceptibility techniques, LifeScale does not rely on the optical properties of the inoculum to determine microbe concentration. LifeScale employs the principle of resonant mass measurement to determine individual microbe mass with the highest possible resolution and accuracy whilst at the same time counting each microbe to yield both the microbe concentration and the mass distribution of the population
It is crucial to track true microbe counts/ml and microbe mass content separately. Microbe concentration predicts growth while mean mass reveals abnormal growth and/or morphology and flags problem samples that could show false resistance. Growth in concentration predicts resistance whereas monitoring mass growth, an optical density surrogate, can falsely indicate resistance.