I think that most researchers experienced static electricity in vitrification or clipping process.
For example, at the final of vitirification, you completed putting grids in a grid button, and then you locked the pin-type-lid round on grid button for preventing grids to rush out of a grid button.
Sometimes, some grids attached itself to the pin-type-lid round because of “static electricity”.
On all such occasions, I detached grids and re-putting a grid in grid button. But detaching is so dangerous for grid quality because tweezers can damage grids.
So, how do overcome “static electricity” in the process vitrification or clipping process ?
I used moisturizing hand cream to applying my hands for removing static electiricity of hands… but there is still limitation for perfectly removing static electricity.
Is it super dry in your lab / geographical region? I have never had this issue - either in the EM suite or in a random lab room. But I work in San Francisco and Seattle.
When you hold the pin lid in the nitrogen to pre-cool it, you could try resting it on a empty button slot on the button rest in the Vitrobot cup. Or, you could get an anti-static gun and shoot the lids a few times just before you grab them with the tool and cool them in the nitrogen.
1 Like
Usually, the humidity of sample preparation room is 3~40%. I think that it’s not super dry.
Your suggestion that I could get an anti-static gun or pad is very good for me.
Thank you…!
Also, do you glow discharge your grids on a glass slide (maybe with a parafilm wrap)?
You could try a metal platform instead, I like the small ones here: PELCO® TEM Grid Holder Blocks
That’s good suggestion. Actually, I doubt parafilm wrapped is maybe one of the reasons.
I will consider it. Thank you!
You could try a piece of foil as a test. It’s interesting because I’ve really never seen the static problem. Maybe just one day in San Francisco, I can’t remember precisely. The humidity is higher there, even inside the controlled areas. Right now it’s at 92% outside in that neighborhood.
I think the grids would be grounded instantly once they are mounted on the vitrobot. It is not important how much charge they carry before this step. Even the metal rod would be large enough to re-distribute the little amount of static charge coming from a grid, greatly reducing its electic potential.
My guess is that the static charge comes directly from your plastic lids. One of my tricks to pickup (rescue) grids from all sorts of liquid is to use a new piece of projector transparency film, which usually carries significant amount of static charge.
In general, static problems come from insulators. On a solid insulator, charge gets partially lost on the surface only when something else is in very good contact with that patch of surface. In contrast, a conductor loses a fraction of its charge as soon as it makes a single point contact with another conductor at a different potential. Then the charge is redistributed based on the size and curvature.
One way to remove the static from fresh plastic is to put the plastic parts in a large volume of salt-containg aqaous solution and connect this solution to an electrical ground. If you do not ground the solution, it should still work for small parts, as long as the volume of the solution is very large. The charge will move from the surface of the plastic parts to the surface of the liquid, because no net static charge can be present inside a conductor. You can also try simply washing the plastic parts under running tap water, maybe with some lab detergent. The general idea is to get the plastic neuralized with some ion. When the plastic is “dirtier” and worn, the static problem often goes away.
Coating the plastic with carbon or metal film might also work. However, I worry if the coating is not strong enough, it might release particles onto the grids. Wrapping the plastic in aluminium foils might be good enough.
switch the button. try examples from other EM labs and pick your favorite. Get a sliding window for 1 grid access at a time, as opposed to complete lid twist-off. This problem was a true nightmare at my previous workplace and a complete non-issue at my current workplace - I assume due to button style.
1 Like
Good suggestions, I respect you. Thank you.