Your “Third Hand” in Mounting Serial Sections on Grids for Electron Microscopy

Abstract

A heavy base 12 cm in diameter supports a vertical rod 40 × 3 cm. To this rod is clamped a horizontal rod 24 × 1.5 an, which bears on its outer end a rack-and-pinion mechanism that carries a clamp. Slow motion can be imparted to the clamp by a knurled pinion knob. For use, a grid is grasped at its edge by a watchmaker's forceps, and the forceps secured in the clamp. The rack and pinion is adjusted to give motion at about 45° and thus allow the grid to be lowered at an angle into the flotation water. While observed under magnification, the ribbon of sections can be manipulated into proper alignment with the grid, the end section fastened to the grid, and the grid raised mechanically to cause the remainder of the ribbon to adhere to it.