Blue Genes - By Val McDermid Page 0,59

at night." He grinned. "It's very straightforward."

The food arrived and we both attacked. "But it doesn't always work, does it?" I asked. "Sometimes they don't do what comes naturally, do they?"

"That's right. Some sperm are lazy. They don't swim well and they give up the ghost before they've made it through to the nucleus of the egg. For quite a few years, when we were dealing with men with lazy sperm, there wasn't a lot we could do and we mostly ended up having to use donor sperm. But that wasn't very satisfactory because most men couldn't get over the feeling that the baby was a cuckoo in the nest." He gave a smile that was meant to be self-deprecating but failed. Try as he might, you didn't have to go far below the surface before Old Man reasserted itself.

"So what do you do now?" I asked.

But he wasn't to be diverted. He'd started so he was going to finish. "First they developed a technique where they made a slit in the 'shell' of the harvested egg," he said, waggling his fingers on either side of his head to indicate he was using inverted commas because he was unable to use technical terms to a mere mortal. "That made it easier. Twenty-five percent success rate. But it wasn't enough for some real dead-leg sperm. So they came up with SUZI." He paused expectantly. I raised my eyebrows in a question. It wasn't enough. Clearly I was supposed to ask who Suzie was.

Disappointed, he carried on regardless as the impassive waiter delivered our main courses. "That involves passing a very fine micro-needle through the 'shell' and deposit-ing two or three sperm inside, in what you could call the egg white if you were comparing it to a bird's egg. And still some sperm just won't make the trip to the nucleus of the egg. Twenty-two percent success rate is the best we've managed so far. So now, clinics like ours out on the leading edge have started to use a procedure called ICSI."

"ICSI?" I thought I'd better play this time. Even pup¬pies need a bit of encouragement.

"Intracytoplasmic Sperm Injection," he said porten¬tously. "One step beyond."

I wished I hadn't bothered. "Translation?"

"You take a single sperm and strip away its tail and all the surrounding jelly until you're left with the nucleus. Then the embryologist takes a needle about a tenth the thickness of a human hair and pushes that through the 'shell,' through the equivalent of the egg white right into the very nucleus of the egg itself, the 'yolk.' Then the nucleus of the sperm is injected into the heart of the egg-"

"Wow," I said. It seemed to be what was expected. "So is it you, the doctor, who does all this fiddling around?"

He smiled indulgently. "No, no, the micro-manipulation is done by the embryologist. My job is to harvest the eggs and then to transfer the resulting embryo into the waiting mother. Of course, we keep a close eye on what the embryologist does, but they're essentially glorified lab technicians. I've no doubt I could do what they do in a pinch. God knows, I've watched them often enough. See one, do one, teach one." It's hard to preen yourself while you're scoffing curry, but he managed.

"So, does the lab have to be on twenty-four-hour standby so you're ready to roll the minute a woman ovulates?" I'd been presuming that Sarah Blackstone did her fiddling with eggs and microscopes in the watches of the night when the place was deserted, but I needed to check that hypothesis.

"We don't just leave it to chance," Gus protested. "We control the very hour of ovulation with drugs. But big labs like ours do offer seven days a week, round the clock service so we can fit in with the lives of our patients. There's always a full team on call; embryologist, doctor, and nurse."

"But not constantly in the lab?" "No, in the hospital. With their pagers." "So anybody could walk into the lab in the middle of the night and wreak havoc?" I asked.

He frowned. "What kind of article are you researching here? Are you trying to terrify people?"

Furious with myself for forgetting I wasn't supposed to be a hard-nosed detective, I gave him a high-watt smile. "I'm sorry, I get carried away. I read too much detective fiction. I'm sure people's embryos are as safe as houses." And we all know how safe that is in 19905 Britain.

"You're right. The lab's always