Improved staining boxes for fast, uniform staining of ultrathin sections on grids

A standard LKB (LKB-Produkter Ab. S-161, 25 Brommma 1, Sweden) grid storage box is converted into several grid staining boxes by sawing the body of the box into segments along rows of its grid storage cavities. The staining boxes can be cut out to any required size or shape. The polymethyacrylate storage box cover is discarded. Covers for the staining boxes are cut from thin sheet vinyl, which is more chemically resistant than polymethyacrylate. Corresponding 2 mm diameter holes are drilled through the vinyl covers and the bottoms of the grid storage cavities of the staining boxes to convert the storage cavities into staining chambers. For staining, the covers are tied to the boxes with sewing thread and the assembled units are put into vials. The separate staining chambers prevent intermingling of and mechanical damage to grids during the staining procedure. Ultrathin sections are more cleanly and uniformly stained in bulk by the use of these staining boxes than they are when stained individually by a standard method.