A system and method for maintaining a suspension of particles within a fluid are disclosed. A container (18) holding a sample having particles and fluid is rotated about its axis at a first calculated rate for a first calculated time interval and then rotated about its axis at a second calculated rate for a second calculated time interval such that the sample flow effects that result maintain a suspension of particles within the fluid and agitate the sample. A cycle of rotation, including the first and second flow rates, may be repeated for a desired number of times for continuous maintenance of the particle suspension. A controller (14) is programmed to rotate a motor (16) connected to a container holder (30) that rotatably drives the container about its axis. Sample (20) may be aspirated from the container and transported to an analytical device (12) while the container is being rotated. Because the rates of rotation of the cycle are relatively slow and because solid body rotation is not achieved during the cycle, the level of agitation that occurs results in only a negligible impact on the analytical device.