[3dem] Gold grid

[Han, Seungil]

Hi Everybody,

     I am currently doing cryo-EM using gold grids purchased from Quantifoil and noticed that there are gold particles within my ice. I have tried cleaning these grids with methanol and noticed that this has significantly changed my freezing condition. Therefore, I am wondering the following:

1. Has anyone encountered gold particles in ice when freezing with gold grids from Quantifoil? If so, then will having gold particles in my ice affect my image processing?

2. Is there a way to clean these particles from the grid? It was recommended that I try cleaning the grids with methanol or plasma cleaner. 

3. I have noticed that these gold grid have a dull side and a shiny side. After washing these grids with methanol, the dull side became shiny. Therefore, what is on the dull side of the gold grid and what have I removed by washing it with methanol?

4. How significant of a change should I expect in my freezing conditions after cleaning my gold grids?

Seungil