How to label your samples,

I have a confession… During a recent internal health and safety (H&S) inspection I was given a minor warning over my lab. I pride myself on keeping our H&S up to date and running a bureaucratically-correct lab. But I failed, I let my lab down, I let myself down and worst of all, I let the large health and safety filing cabinet down.

Like any good health and safety system we have a labelling policy. And amazingly for us, it goes beyond “must have a label” – which is the policy in most labs and explains why they are full of tubes labeled “Sample 1”, “46Xb-2” and “Jeff’s DON’T TOUCH”. The last is particularly worth paying attention to bcause Jeff rides a motorbike and you don’t mess with a biker’s lab samples.


In my lab, I try to insist that a label has several key things on it to help work out first and foremost, if the mysteriously substance is going to explode and then who I should shout at if it does explode later. So the first thing that absolutely must be on it is initials. If two people in the lab have the same initials then they draw straws and one of them legally changes their name.

Next is the date it was created/decanted. Dates are important because some tubes contain life that is sentient enough to want to celebrate anniversaries of its existence at the back of the fridge. It is also incredibly helpful in tying up the prep to experiments and lab book notes (assuming you bother to put a date in the lab book). In some cases we put best before dates on but in most cases we either don’t know or it’s a lot longer than our project.

Hazards are tricker to do as there are quite a few of them and we have almost all of them in the lab. I did try drawing symbols but people liked the cartoons so much it slightly counterproductively encouraged people to pick up the tubes. Instead we now do colour coded pens and put up a legend on the lab wall as apparently it’s not obvious to everyone that Blue means solvent, and Red means acid.

Lastly is what is actually in the tube. This can be tricky as some names are longer than the 600 word limit of this article. Some times we use codes but I try to now make sure the translation for these codes exists in more than just a single lab book (an almost always indecipherable document). I also insist that people put concentration on the bottle, it’s amazing how optional people seem to think that is. Which as we regularly using both 20% and 0.5% H2O2 you’d think people would realise it’s a bit required to know which is which.

I know some people that add on lab book numbers and pages but I use an electronic lab book which just gives me links and I think scrawling a URL on an eppendorf tube is a bit beyond my calligraphy skills. Although as I write this, I am thinking I could get a label printer and start covering stuff in QR codes.

So what exactly was wrong with my labels? Well you may have your own opinions on whether or not the above is a sensible policy and may in fact be frowning at this article in disappointment at the terrible labels mistakes I’m making. But the actual mistake I had made was that I hadn’t used university printed labels (they have a poorly sized CHEMICAL label at the top) to write all this information on. Like some dangerous maverick I’d been writing it all on white labels (and even directly on the bottle *gasps*). It’s a miracle I’m not dead.

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