Abstract: The present invention is a cuvette assembly for use in optically measuring at least one characteristic of particles within a plurality of liquid samples. The cuvette assembly includes a unitary body made of a single type of transparent material. The unitary body includes a plurality of optical chambers for receiving the liquid sample, an entry side wall for allowing transmission of an input light beam into the respective liquid sample, and an exit side wall for transmitting a forward scatter signal caused by the particles within the respective liquid sample. Each of the plurality of optical chambers is separated by internal walls of the unitary body.

Abstract: A method for detecting and counting particles suspended in fluids, such as bacteria suspended in urine, utilizing dynamic features of the suspended particles and employing light scattering measurements. The disclosed method is suitable for determining the susceptibility of bacteria to antibiotics. A cuvette for detecting bacteria in fluids, which is especially suited for the light scattering measurements, is provided.