Abstract: Sampling apparatus designed for aspirating, diluting and mixing a small sample of fluid in precise amounts and delivering the mixture to a scientific apparatus at a place remote from the place of aspiration. Operation of the device may be manual but is preferably automatic. The apparatus is designed to process a plurality of sample fluids with no cross-contamination between samples. In essence, the apparatus is a fluid handling system including a sample pick-up assembly in fluid communication with an automatic valve assembly having two operative positions. The automatic valve assembly is in fluid communication with a dilutor assembly having a sample pump and a diluent pump operable by a common means. A mixing and delivery assembly is also in fluid communication with the automatic valve assembly and includes a cup designed for bidirectional rotation with an annular space about the cup.