Many of the newer flanged plastic stoppers are excellent. Microscope slides are usually stored in wooden or plastic boxes obtainable from biological supply houses. The inner sides of the boxes are slotted to hold the slides vertically and to separate them from one another. Slide boxes are available in sizes made to hold from 50 to 100 or more slides. If the slides are to be stored vertically, it is important that they be thoroughly cured before storage or the cover glasses may slip.
Some workers store the slide boxes on their sides so that the slides rest horizontally.
This is especially desirable if the slides are made with Hoyer's medium, which may become soft under very humid conditions. Several slide-filing systems are available from suppliers, but whatever system is used, care should be taken to assure that additional similar equipment will be available in the future for expansion of the collection. Small plastic slide boxes, usually made to hold five slides, are convenient for keeping slides in a unit-tray system although it is usually best that pinnned specimens and slides not share the same unit. This is especially desirable when genitalia are mounted on slides, because it is readily apparent to visiting researchers examining the pinned specimens that such slides are available. Larger collections usually use the unit-tray system, with various sizes of unit trays made to fit into a drawer.