A fixed reference edge system that guides a glass slide from a slot of a slide rack onto a scanning stage and guides the glass slide from the scanning stage into the slot of the slide rack. In an embodiment, the fixed reference edge has a first side that is parallel to a side of the slot of the slide rack. The system comprises an assembly that includes a push bar configured to push the slide from the slot onto the scanning stage, and a pull bar configured to pull the slide from the scanning stage into the slot of the slide rack. When the slide is pulled into the slide rack, the long edge of the slide is pressed against the first side of the fixed reference edge to maintain a parallel orientation between the slide and the slot of the slide rack.