An apparatus for handling sample tubes is presented. The apparatus comprises a sample tube tray, a sample tube individualizer, a first conveyor, a second conveyor, a sample tube buffer, and a sample tube rack inserter. The sample tube tray stores sample tubes in bulk commodity. The sample tube individualizer sequentially unloads single sample tubes from the sample tube tray and sequentially provides the unloaded sample tubes to the first conveyor. The first conveyor conveys the sample tubes to the sample tube buffer. The sample tube buffer buffers the sample tubes provided by the first conveyor and provides buffered sample tubes to the second conveyor with a predeterminable, constant, sample tube rate. The second conveyor conveys the sample tubes to the sample tube rack inserter. The sample tube rack inserter inserts the sample tubes into a sample tube rack.