Bacteria growth rate determn. in the presence of antibiotics - with fluid cavitiesin transparent disc monitored by photocells

摘要

An appliance for determining bacterial growth in the presence of growth inhibitants comprises a source of radiation such as light; a disc of material transparent to the mentioned radiation, with a peripheral surface, and having a number of cavities for holding a fluid contg. viable bacteria, one being positioned at its centre whilst the others are spaced out close to its periphery, the outer cavities having in addn. to the viable bacteria, a growth inhibitant such as an antibiotic; holders for the disc and the light source able to move one relative to the other, the light source being located w.r.t. the periphery of the disc, so that its rays can penetrate one of the cavities and be scattered along a path at an angle to the first; means close to the disc of measuring the radiation along the second path and determining its intensity; and circuits connected with the meters assigned to each cavity for processing the signals produced. Device considerably reduces the time necessary for determining the rate of growth in the presence of antibiotics, from e.g. the previous 24 hrs. to 4 or 5.