Modified Hiraoka TEM grid staining apparatus and technique using 3D printed materials and gadolinium triacetate tetrahydrate, a non-radioactive uranyl acetate substitute.

The Hiraoka transmission electron microscopy (TEM) grid staining apparatus, which allowed multiple grids to be batch stained together on a plate, is no longer commercially available. Because the need for such a device still exists, we developed a modified Hiraoka TEM grid staining apparatus by combining a Leica AC20 grid plate holder with a modified 3D printed grid loading holder and trays lined with ParafilmR. This apparatus was then used to test a post-section contrasting method that uses gadolinium triacetate tetrahydrate solution, a non-radioactive uranyl acetate substitute, which produces similar staining results to uranyl acetate when used with lead stain in mouse ocular tissue for TEM.