The Bal-Tec MED 010 Planar-magnetron sputtering device is equipped with a turbo-molecular pump, 2 electron-beam guns, a quartz crystal thickness monitor, and an adaptor for the Gatan 626 cold-stage. This system is used for controlled freeze drying, sputter-coating a thin layer of Cr, W, or Pt at low temperature for high resolution cryo-SEM.
Freeze-fixed samples may then be coated in the cryocoater. The upper few micrometers of water are first sublimated, and then the specimen is coated with a thin layer of platinum (or other metal) to provide conductivity and some protection from beam damage. The samples are held in a Gatan cryostage for the coating and examination in the Hitachi S-900 FESEM. Freeze-fixed samples may also be freeze-dried, coated in one of the other coaters, and then examined at room temperature in the Hitachi LaB6 SEM.