Cleaning Glass Coverslips

Overview

Small and efficient protocol to clean common glass coverslips, in order to remove dusts and industrial residues attached to them.

Supplies

Glass Coverslips for Microscopy

Some metallic multiple coverslips holder

Three pyrex beakers large enough to contain the coverslips holder

One pyrex beaker large enough to contain one of the precedent

Reagents

Piranha mixing made of

30% {v/v} Hydrogen Peroxide (Sigma Aldrich H1009 )

70% {v/v} Sulfuric Acid (Fluka 84720)

Equipment

A chemistry hood

A Milli-Q water production machine

A Lab Coat

EyeGlasses

Latex Gloves

The steps 1 to 4 have to be perfomed under the hood

Put the glass coverslips on the holder, eventually with latex gloves
- Put the holder in one of the smallest beakers and put this beaker in a bigger one. This is useful when the Piranha mixing overflows due to the temperature.
The total volume of Piranha should be large enough to fill the beaker up to the coverslips height, at least.
- Pour the volume of Sulfuric Acid in the beaker containing the coverslips holder
- Pour the volume of Hydrogen Peroxide in the beaker.
Wait for 10 minutes. The mixing can bubble a lot. Remove the slides at this point. If you don't, the Piranha can attack the metallic holder, making solution green and dirty.
Remove carefully the slides holder and put it quickly in a beaker full of deionized water.
Rinse at least 8 times the coverslips holder by changing it quickly and without any shock from one beaker to another filled with deionized water.
We you finished to rinse the slides, you have to let them in deionized water as long as you don't use it

The reaction is HIGHLY EXOTHERMIC, so be careful for the step 2.
As soon as the coverslips are out of the Piranha solution, it's important that they NEVER remain at the air. If so, the coverslips could be covered by dust.
At the very end of the process, the slides should be completelly wetted by water, with no contact angle.