Samples, e.g., cell suspensions or protein preparations, are incubated with MACSiBead™ Particles. Subsequently, the tubes containing the samples are placed in the extremely strong magnetic field of the MACSiMAG™ Separator. Within a few minutes, the MACSiBead Particles, 3.5 μm in size, together with the labeled material (e.g. certain cells, endotoxin) adhere to the tube wall. The supernatant, which is depleted of the labeled material, can be removed.