Pipette travel limiting apparatus

An apparatus for limiting pipette head travel with respect to a ground surface, and for limiting insertion of a pipette into a tube, has a top surface including at least one aperture. Each aperture selectively and concurrently accepts a corresponding pipette head of a pipette device therethrough. A bottom surface extends substantially parallel to the top surface and selectively contacts the ground surface. A plurality of side surfaces extends transversely between the top and bottom surfaces. The side surfaces each have a predetermined height correlated with a desired minimum approach distance of each pipette head toward the ground surface. The top, bottom, and side surfaces collectively enclose and define a spacer volume, at least partially through which each pipette corresponding to a pipette head extends. Methods of limiting pipette head travel with respect to a ground surface, and of limiting insertion of a pipette into a tube, are also provided.