We've all been there. Darkness has fallen outside the lab, and you're the last one left, gamely trying to finish off that final experiment — feeling that half-smug, half-martyred feeling of Suffering for Your Art. Only a few minutes before, your boss poked his head in and said goodbye on his way out, noting your solitude and nodding with approval: score. You've put something particularly loud, grungy and offensive on the MP3 player because no one is around to complain. The lab is your kingdom; the secret molecules of life are arrayed before your masterful hands like tame dogs, jumping over barriers and through hoops with gleaming fur and slavish, devoted eyes. You've added all but one of the ingredients into your pre-mix, and have just opened the communal freezer to find the enzyme, and …..

The tube is empty. Not empty as in, there are a few droplets of liquid safely sequestered in the cap for this precise contingency. But empty as in, you spin it down for a minute and the tube is so bone-dry that you can practically hear the swoosh of tumbleweed echoing off its plastic walls.

That empty.

Of course, a number of things start running through your mind at this point. Obviously you're worried about your experiment, and frustrated that you're going to have to postpone it until tomorrow. You worry about what your boss is going to say in the morning when he finds out that your crucial construct has been delayed by another 12 hours. But chiefly, your mind is reeling at the inconsiderate behaviour of the labmate who left you in this situation.

It's bad enough to not take action when a stock is running low. And yes, it's even worse to use up the last bit of something, throw away the tube and not order more. But someone actually put an empty tube back into the freezer. Deliberately, by all accounts. And quite possibly accompanied by a sustained bout of maniacal laughter.

Now, I know what you're thinking. Your first instinct is to storm over to the Whatman paper, rip off a big sheet, find the most luridly red lab marker pen around and let loose all of your anger, irritation and self-pity into the mother of all rant notes, crafted with one part sarcasm, one part passive-aggressive guilt-trip and eight parts sheer vitriol.

But ladies — and, to be fair, those gentlemen who might be similarly inclined — you must resist.

I repeat: put down the pen and step away from the freezer. That's right: nice and slowly. Now put that Whatman paper back into its cardboard box (someone might need a piece that size one day, and it doesn't grow on trees. Okay, it actually does, but never mind.). Leaving a note will do absolutely no good, beyond the release it gives to your own blood-boiled state. On second thought, by all means, get it out of your system, honey — but then crumple up the note and throw it away (into the paper recycling bin which is, by the way, rather ironically festooned with a recent nasty note about inconsiderate dolts chucking their food remains therein). Leaving a rant note taped accusingly to the freezer will not change behaviour — all it will do is make you look hormonally challenged, reinforcing every stereotype that your male colleagues might have about you, and irritating your more relaxed female colleagues. And yes, everyone does know what your handwriting looks like.

Now, it took me several years of post-doctoral servitude to come to this philosophical point. Over the years I've seen some amazing examples of selfishness, greed, messiness and laziness in the Ivory Tower. And I was exaggerating for effect; I know that not all men are messy, and not all women are tidy and considerate. There are some trends, to be sure, but that's not what I want to discuss today. The sad truth is that although we would all like to think that the lab is a team, labouring together towards a common goal and looking out for each other no matter what, it simply isn't true. Like all human endeavours, how committed you are to altruistic group behaviour runs on a continuum from terribly concerned, prioritizing communal spirit over self-preservation (e.g. the graduate student who volunteers, out of the kindness of his heart, to make up the buffers for everyone else), to couldn't-give-a-monkey's-uncle about anyone else but themselves and their own experiments (e.g. the post-doc who steals other people's buffers because she feels too important to make her own).

And, just as our animal origins are only thinly restrained behind the veneer of civilisation, one is never too far from the repugnant end of that scale. Only the other day as I was dashing from the lab, late for my bus, I noticed that I'd left the gel area a shambles. And although the urge to leave it until morning was strong, I had to pause and sternly remind myself that not cleaning up would be terribly rude, especially with all that buffer on the floor threatening to break someone's neck. We wouldn't be human if we weren't perpetually tempted to take the easy way out. But the way I see it, since we went to all the trouble of dragging ourselves out of that warm and cosy primordial soup in the first place, we might as well try to get along.

Others do not seem to have this gene. You can leave a thousand notes, make pointed remarks at lab meetings about ‘someone’ having forgotten to recap the acetic acid, to remove mouldy plates languishing in the tissue culture incubator, to switch off the UV lamp on the microscope over the weekend, but the sad truth is that it won't make a blind bit of difference. We recently removed someone from the weekly tidying rota because she never, ever remembered to do it and by midweek, some other frustrated soul would end up covering for her. It pained Dr Keen to be rewarding someone for laziness, but at the end of the day, the lab needs to run smoothly and he considered it to be less fuss just to remove her from the loop.

And besides: the recalcitrant oafish colleague will not, in the end, go unpunished. So the next time you wisely decide to leave a flagrant crime un-noted, just remember that its perpetrator will ultimately get his or her just desserts. They might find it difficult to persuade someone to lend them that crucial plasmid, to gather allies for political skirmishes, to find colleagues for collaboration, or a positive referee for a job application. Because when it comes down to it, nobody respects a lazy, selfish slob, and being respected, in science, is part of what you need to succeed.

And, hey — look on the bright side. If that missing enzyme forces you to cancel the rest of your experiment, why not just go home to some well-deserved food, rest and an enjoyable evening on the sofa in front of the telly? After all, it's only science!