A pipetting device having a modular pipetting unit including a pipetting tip for pipetting of fluid samples and a pump conduit for transferring a negative or positive pressure to the pipetting tip is disclosed. The pipetting tip and a portion of the pump conduit adjoining the pipetting tip mutually define a fluid sample conduit for receiving the fluid samples. The modular pipetting unit is detachably attached to an automated positioning device for positioning the modular pipetting unit. A system and method for pipetting of fluid samples using such a pipetting device are also disclosed wherein pipetting of the fluid samples is performed in such a manner that each pipetted fluid sample volume is smaller than a volume of the fluid sample conduit.