It started in the radiation suite.

Two of the grad students were in the 'hot room' with some radiolabelled tritium. The stuff is innocuous enough, despite its 12-year half-life, but there had been an inexplicable error at the manufacturer. For reasons that may become clear if there is anything left of the judicial system, 'Chad' in Dispatch had got his H's and his Pu's all mixed up, and had slipped a nice nugget of plutonium-239 in amongst the corn packing chips.

Of course, back in the radiation suite, the Geiger counter had gone nuts, but being biologists unused to the true significance of a Geiger counter ticking away like a Rolex concession in Macy's, the two students sat there for a good couple of hours poking the counter and waving its sensor at some of the other radioprobes in the fridge to work out why the device appeared to be broken. Sadly, they never made it out of the room. Well, their souls never did. Big Dave went down first, probably at the point when his liver took on the consistency of mushroom soup, and the vomiting Sean was not far behind.

What happened next was out of eyesight of the CCTV cameras. Presumably, they both lay twitching on the dusty, tiled floor until their human essence drifted out over the flood-resistant door threshold and out into the University air conditioning system. Some kind of energy in the room presumably reanimated them. A rad suite is full of all sorts of interesting energy, from the electric lights to the carbon-14. I suppose the whacking great lump of 239-Pu didn't help matters.

Anyway, after about three hours of restful death, and just before the point when most mortals start to undergo rigor mortis, the bodies of Dave and Sean stirred, and then jerkily rose to their feet. And what a sight they were. One of Dave's eyes had melted, and that liver I mentioned was oozing out through an enormous open sore in his side. Sean had clearly hit the floor quit hard when he died – the right side of his skull was caved in, and his right arm hung loose and broken at his side. Both of them had the dark, sunken eyes (one in Dave's case) that you have probably seen by now, either on the news or staring at you as you run home from your local fortified 7-Eleven. Both of their lab coats were a mess of dried blood and yellow adipose tissue. Not even Initial Services could have dealt with a laundry challenge like that.

So, what follows is my report on the success and failure of the various means a lab worker might have at their disposal for stopping a Category 2 zombie attack.

It starts with the raised threshold of the rad suite. Once Dave and Sean had stopped banging their heads against the door of the hot room, one of them managed to locate the handle and swung the door open into the main lab of the suite. This was the point at which I looked up from my work and realized something was amiss. Both zombies were ashen-faced and emitting a low growl. I figured that if I stayed put, I might sustain the classic clinical presentation of a neck bite, so I quickly gathered what I could of my notes, and made for the exit.

Dave lunged forward first and tripped over the raised threshold. Sean fell over Dave and landed flat on what was left of his face, knocking out most of the teeth from his already rotting gums. Looking at the pair of them clumsily trying to get back to their feet made me speculate that this episode might actually be completely survivable.

As Dave lumbered back to his full height and snarled at me, I picked up one of the wee microfuges and threw it at his head. It stuck there for a moment, lodged in a gory pit where his nose had once been before dropping to the floor with an expensive-sounding clatter. Dave snarled again, a bit more nasally this time, but clearly unaffected by the equipment projectile. Sean was up and limping towards me now; and with both of them making their slow and deliberate way towards me, I nipped out of the rad suite to put some distance and thinking time between them and me. Not so fortunate was Chloe, the lovely, petit French PhD who was doing some interesting work on DNA damage. She walked into the suite the moment I emerged from it, and collided breasts-first with Dave. He was on her in a second. He'd always had a bit of a thing for her, but probably didn't foresee that his first kiss would be a fangy tear at her slender white neck. Now there were three of the bastards to contend with.

Thinking that a collision with a really hefty piece of equipment might be just the ticket, I dashed in to the next lab and found me a spectrophotometer on a castor trolley. Flicking the castor brakes off, I push it out of the room and lined it up in the corridor. With a brief and embarrassed-sounding battle cry, I charged the trolley at the gruesome trio, noticing in passing that Chloe's looks had deteriorated markedly. The trolley rammed into Sean, ripping off his already broken arm, and mashing Chloe's leg into a grisly mess. Dave leant over the trolley to grab me, but I was able to flick the mechanical switch that opened the lid, and it sprang up and hit him square in the throat. His windpipe collapsed and the snarling ceased, but he was by no means impotent. Abandoning the trolley, I retreated back up the corridor.

Sean and Dave clambered awkwardly over the abandoned machine, Sean carrying his severed arm with his one good hand. Chloe had gone into a side room and was drinking the blood of the now catatonic stores manager, Ray. Once Dave and Sean had cleared the obstacle, Chloe and Ray followed slowly behind, and now I had four zombies after me in a 1-mph death chase.

Now, anyone who knows me from the lab will know that I prefer ice to fire. Blowing things up is great fun, but freezing them is way cooler. Our own lab has a great stash of liquid nitrogen in a large vat, about the size of your classic witch's cauldron, and mounted on a cradle that allows it to tip. This is also on wheels, which makes it a great anti-zombie weapon. Rolling this out into the corridor, I noted something interesting. All four of the ghouls stopped dead, so to speak, in their tracks. There was a glimmer of recognition in their seven eyes and a flash of fear across their ruined faces. Somewhere in their addled brains lay the capacity to understand that liquid nitrogen meant trouble.

I lined up the nitrogen vat, removed its blue, insulated lid and tipped the lot onto the floor. Unfortunately, Vernon, the post-doc that I share lab space with, had spent the morning freezing tissue samples and had not left a lot of nitrogen in the vat. The sizzling, steaming puddle of icy fluid spread rapidly across the floor, lubricated by its own cushion of frictionless nitrogen gas. It sloshed up against Dave's feet and frosted his trainers with a layer of condensed icing. He faltered for a moment before crashing face first to the floor, leaving his brittle and severed feet frozen to the tiles. The rest of the nitrogen fizzled out in a crescendo of hissing.

As the gas cleared, I was able to assess the damage I had wrought. Dave was down, but not out – his foot-less body was clawing its way across the floor towards me. Sean and Ray were unharmed and growling steadily. Sean threw his arm at me, which glanced off the wall and dropped at my feet, still moving. The once shy and retiring Chloe, her lithe figure caressed by the remaining wisps of white gas, was locked in a chewing embrace with the Professor's secretary. I picked the vat up off its mounting and brought it crashing onto Dave's head, smashing his coronal suture, and springing off his sphenoid bone. Another go demolished his frontal bone and both the supraorbital processes. That was a zombie who was not getting up. However, despite my victory over Dave, I was still faced with the same number of zombies due to Chloe's phebotomic promiscuity. What I needed here was a lab-based WMD – something that would see off my colleagues once and for all and avoid a zombie apocalypse.

Dashing away from the living dead, I came up with the simplest and most brilliant idea. What is the most dangerous piece of equipment in your average biological lab? An unbalanced ultracentrifuge, obviously. Unfortunately, the nearest one lay several rooms away down the corridor. As I ran towards it, Sean, Ray, Chloe and Mrs Huggins peeled off into the other labs and press-ganged more of their colleagues. Hampered a little by the lack of an arm, Sean stopped by the small animal unit and ate the rats.

In a minute or so, I was at the centrifuge and setting it up. I had no samples to hand, so I simply loaded one of the rotor cups with water, and closed the lid of the machine. I then set the speed to 800,000g, and looked to see how far the zombie army had advanced on my position. Clearly, there had been some recruiting going on, as now there were about 20 groaning scientists, admins and students in stained lab coats making their painful way up the corridor.

Mindful that the centrifuge was possibly more likely to kill me than them, I ripped a digital timer off the plug of a waterbath and set it to three minutes – roughly how long I thought it would take for the horde to cover half the distance between their current location and the centrifuge. I reckoned that if the machine started then, it would be up in the dangerously unstable range by the time the first zombie could touch it.

Once the machine was rigged up, I climbed onto the worktop behind it and slunk out of the window. The zombies groaned louder than ever, thinking they had lost their prey. I stayed at the window with my face clearly visible as bait. Stiffening their lust-driven resolve, the zombies shuffled forward, unaware of the danger that awaited them.

At the moment that the lifeless, walking corpse of Roger from Lab 2 crossed the half-way mark, the ultracentrifuge started to grind. The grind became a whirr, and the whirr became a whistle. The rotor was hurtling around inside the machine at breathtaking speeds. As it reached the 100g mark, the machine started to make a faint knocking sound, which became louder and more frequent as the rotor went faster and faster: the seriously out-of-balance rotor was reaching the danger point. The machine reached a deafening crescendo and suddenly flew across the floor. I ducked below the window, but not before seeing the three tons or so of steel and plastic pulverize the front rank of zombies. As I dashed to safety, the machine tore itself apart, swinging lethal strips of metal and wire at the necks and bodies of the remaining ghouls. Piece of masonry were smashed from the walls, and the corridor of the Department became a bewildering mess of arms, legs, heads and brick dust. The lethal metal dervish continued to flail the zombies to a pulp until all of its kinetic energy was spent.

The corridor fell silent.

Of course, I didn't kill them all, or I would not be writing this from a concrete bunker under the air force base. If I had to guess who survived, I would say it was Sean. There were an awful lot of rats in that room, and he was probably still gorging himself while the others were being bifurcated by the centrifuge. Still, there were valuable lessons to be learned:

1. The raised threshold of a rad suite is a trip hazard.
2. A microfuge is not that expensive – every lab should have two.
3. The lid of a spectrophotometer may have an eager spring on it – take care.
4. Always fill up the liquid nitrogen after use.
5. An unbalanced ultracentrifuge is incredibly dangerous.