How do you clean your coverslips?
Posted: Sat Jun 27, 2020 4:56 pm
Whenever I open a new pack of coverslips they are always dirty (mostly specks but sometimes residue as well). Normally I'd give them an alcohol wipe and that's fine for wet mounts.
Sometime ago I made attempts to arrange diatoms on adhesive-coated coverslips. I cleaned them in 2M sodium hydroxide for a few hours, then rinse extensively with DI water and eventually store them in ethanol. The coverslips were really clean, the only issue was that their thickness was hovering around 0,14-0,15 mm (it was not indicated but I suspect these are #1 thickness)
Now I tried the same procedure with high precision #1.5H coverslips from a different manufacturer and it seems that the sodium hydroxide significantly alters the glass surface. There is an irregularly distributed hazy fog-like layer. I have the feeling that the hydroxide is etching the surface, maybe destroying the nice finish (the longer I leave them in the hydroxide solution the more noticeable it gets). I don't know why it wasn't a problem with the previous coverslips, its likely different type of glass used to make them.
What protocol do you follow when you have to clean coverslips for more critical applications like darkfield microscopy or diatom arrangements? Boiling piranha mix is something I'd prefer not to deal with but it probably works best.
Sometime ago I made attempts to arrange diatoms on adhesive-coated coverslips. I cleaned them in 2M sodium hydroxide for a few hours, then rinse extensively with DI water and eventually store them in ethanol. The coverslips were really clean, the only issue was that their thickness was hovering around 0,14-0,15 mm (it was not indicated but I suspect these are #1 thickness)
Now I tried the same procedure with high precision #1.5H coverslips from a different manufacturer and it seems that the sodium hydroxide significantly alters the glass surface. There is an irregularly distributed hazy fog-like layer. I have the feeling that the hydroxide is etching the surface, maybe destroying the nice finish (the longer I leave them in the hydroxide solution the more noticeable it gets). I don't know why it wasn't a problem with the previous coverslips, its likely different type of glass used to make them.
What protocol do you follow when you have to clean coverslips for more critical applications like darkfield microscopy or diatom arrangements? Boiling piranha mix is something I'd prefer not to deal with but it probably works best.