This test specimen consists of 0.261 micron diameter Latex Spheres shadowed with gold.
The gold forms islands of electron dense material suitable for determining instrument resolution by the particle separation method.
The fines particles can be usually be located around the edges of the "shadow" areas.
CARE OF THE SPECIMEN:
Use a binocular microscope when removing the specimen from the plastic vial to ensure that only the extreme edge of the grid is held in the forceps. Place the grid directly into the microscope specimen holder if possible. If the grid must be laid down, do so only on a lint free surface with a darker, more reflective side of the grid facing up (the specimen side).