All microscopes are designed to include a stage where the specimen (usually mounted onto a glass slide) is placed for observation. Stages are often equipped with a mechanical device that holds the specimen slide in place and can smoothly translate the slide back and forth as well as from side to side. A stage can be classified according to design and functionality. In the simplest case, the plain stage consists of a rectangular or square design \containing several clips to hold the specimen slide.
The stage is a typical rectangular stage with the added feature of a specimen slide translational control device commonly referred to as a mechanical stage. This mechanical stage contains controls for right-handed microscopists that allow the movement of the specimen slide in both the X (right and left) and Y (back and forth) directions so the microscopist can examine the entire microscope slide (secured to the stage with the slide holder). Similar mechanical stages are available with the translational control knobs situated on the left-hand side of the stage for left-handed microscopists. The stage also contains a rather large opening in the center to allow light from the condenser to pass through the specimen (the stage opening). The stage is also equipped with a locking control that allows the stage to be fixed into position with respect to its rotation around the condenser axis. Graduated locator marks positioned on the mechanical portion of the stage allow the microscopist to note the location of important specimen details, allowing easy return to the area for additional observation or photomicrography.
A simple (commonly termed "plain") microscope stage. This stage contains an opening to admit light from the condenser, several mounting holes for a mechanical stage, and two clips that secure the specimen slide in place for observation under increasing magnification (changing of objectives) and for photomicrography. The stage is also equipped with a locking control that can fix the position of the stage. This stage is very useful for quick examination of specimens, but is very difficult to use with higher power objectives (above 20X). At high magnification, small translations of the specimen slide will usually throw the features of interest completely out of the viewfield, and attempting to relocate them can lead to frustration. Auxiliary mechanical stages attached to a simple stage can allow for minute translation of the specimen slide, making it easier for the microscopist to find specific areas on the slide.
