Ideally, your tissue culture incubator should be polished stainless steel, gleaming and immaculate like a surgical theatre. And I am sure you keep it in order, like new. It’s just sometimes you start in a lab where the incubators already have brown spots – rust.
There’s Rust in My Incubator!
Usually rust occurs because of incorrect cleaning. Some careless person, remembering what his mum uses in the kitchen, used bleach for cleaning. Although the sticker on the door says “no chlorine ions,”and bleach vapour is toxic to the cells. Or somebody left Virkon solution on allowing it to eat at the surfaces, not wiping with alcohol afterward. Or even another somebody put copper salt into the water jacket for disinfection, and copper is corrosive.
The good news is that the rust spots are not harmful to your culture on their own, as the rust does not get into the sealed tissue culture vessels. The bad: rust spots provide a good shelter for bugs, which will get there one day, and from the rust into your tissue culture.
Also, although not alive, the rust spreads. If you do not deal with the problem as soon as you see it, one day your incubator will be covered in rust flakes. The people who use the incubator will start spreading it around like dandruff.
How to Get Rid of Rust
So what can you do about the rust? If the rust is on a removable part of the incubator, it may be better to replace it. Look in the manual for the part number (remember it’s cheaper to prevent contamination!). If the rust spots are on removable main parts of the incubator you can use dilute hydrochloric acid (chloride, not chlorine ions) to clean it. But be careful not to use concentrated acid because it gives off harmful fumes. You can also sand off the rust patches using scouring pads, the sort you buy for the kitchen – quicker said than done, but your tissue culture worth applying some elbow grease.
You can also prevent the rust from appearing in new places sticking— and insisting others stick to— to the protocol for incubator maintenance (no harsh solutions). You can even buy one of the anti-rust solutions for the water jackets supplied by the incubator manufacturers. Either way, rust in your incubator is not an incurable problem—with a little work on your part!