In the corner of the small lab is a locked door with a colorful sign taped to the front: "$100 Genome Room--Authorized Persons Only." BioNanomatrix, the startup that runs the lab, is pursuing what many believe to be the key to personalized medicine: sequencing technology so fast and cheap that an entire human genome can be read in eight hours for $100 or less. With the aid of such a powerful tool, medical treatment could be tailored to a patient's distinct genetic profile. TR10: $100 Genome
Han Cao's nanofluidic chip could cut DNA sequencing costs dramatically.
By Lauren Gravitz
Despite many experts' doubt that whole-genome sequencing could be done for $1,000, let alone a 10th that much, BioNanomatrix believes it can reach the $100 target in five years. The reason for its optimism: company founder Han Cao has created a chip that uses nanofluidics and a series of branching, ever-narrowin?g channels to allow researchers, for the first time, to isolate and image very long strands of individual DNA molecules.
If the company succeeds, a physician could biopsy a cancer patient's tumor, sequence all its DNA, and use that information to determine a prognosis and prescribe treatment-- all for less than the cost of a chest x-ray. If the ailment is lung cancer, for instance, the doctor could determine the particular genetic changes in the tumor cells and order the chemo?therapy best suited to that variant.
Cao's chip, which neatly aligns DNA, is essential to cheaper sequencing because double-stranded DNA, when left to its own devices, winds itself up into tight balls that are impossible to analyze. To sequence even the smallest chromosomes, researchers have had to chop the DNA up into millions of smaller pieces, anywhere from 100 to 1,000 base pairs long. These shorter strands can be sequenced easily, but the data must be pieced back together like a jigsaw puzzle. The approach is expensive and time consuming. What's more, it becomes problematic when the puzzle is as large as the human genome, which consists of about three billion pairs of nucleo?tides. Even with the most elegant algorithms, some pieces get counted multiple times, while others are omitted completely. The resulting sequence may not include the data most relevant to a particular disease.
In contrast, Cao's chip untangles stretches of delicate double-stranded DNA molecules up to 1,000,000 base pairs long--a feat that researchers had previously thought impossible. The series of branching channels gently prompts the molecules to relax a bit more at each fork, while also acting as a floodgate to help distribute them evenly. A mild electrical charge drives them through the chip, ultimately coaxing them into spaces that are less than 100 nanometers wide. With tens of thousands of channels side by side, the chip allows an entire human genome to flow through in about 10 minutes. The data must still be pieced together, but the puzzle is much smaller (imagine a jigsaw puzzle of roughly 100 pieces versus 10,000), leaving far less room for error.
The chip meets only half the $100-genome challenge: it unravels DNA but does not sequence it. To achieve that, the company is working with Silicon Valley-based Complete Genomics, which has developed bright, fluorescently labeled probes that bind to the 4,096 possible combinations of six-letter DNA "words." Along with ?BioNanomatrix's chip, the probes could achieve the lightning-fast sequencing necessary for the $100 genome. But the probes can't stick to double-stranded DNA, so Complete Genomics will need to figure out how to open up small sections of DNA without uncoupling the entire molecule.
BioNanomatrix is keeping its options open. "At this point, we don't have any exclusive ties to any sequencing chemistry," says Gary Zweiger, the company's vice president of development. "We want to make our chip available to sequencers, and we feel that it is an essential component to driving the costs down to the $100 level. We can't do it alone, but we feel that they can't do it without this critical component."
Whether or not BioNanomatrix reaches its goal of $100 sequencing in eight hours, its technology could play an important role in medicine. Because the chips can process long pieces of DNA, the molecules retain information about gene location; they can thus be used to quickly identify new viruses or bacteria causing an outbreak, or to map new genes linked to specific diseases. And as researchers learn more about the genetic variations implicated in different diseases, it might be possible to biopsy tissue and sequence only those genes with variants known to cause disease, says Colin Collins, a professor at the Prostate Center at Vancouver General Hospital, who plans to use BioNanomatrix chips in his lab. "Suddenly," Collins says, "you can sequence extremely rapidly and very, very inexpensively, and provide the patient with diagnosis and prognosis and, hopefully, a drug."
“You wait till Larry comes and I tell him my theory!” The bids, duly sealed, were given into the keeping of the commissary officer to be put in his safe, and kept until the day of judgment, when all being opened in public and in the presence of the aspirants, the lowest would[Pg 188] get the contract. It was a simple plan, and gave no more opportunity for underhand work than could be avoided. But there were opportunities for all that. It was barely possible—the thing had been done—for a commissary clerk or sergeant, desirous of adding to his pittance of pay, or of favoring a friend among the bidders, to tamper with the bids. By the same token there was no real reason why the commissary officer could not do it himself. Landor had never heard, or known, of such a case, but undoubtedly the way was there. It was a question of having the will and the possession of the safe keys. "Well, I believe our boys 's all right. They're green, and they're friskier than colts in a clover field, but they're all good stuff, and I believe we kin stand off any ordinary gang o' guerrillas. I'll chance it, anyhow. This's a mighty valuable train to risk, but it ought to go through, for we don't know how badly they may need it. You tell your engineer to go ahead carefully and give two long whistles if he sees anything dangerous." "Fine-looking lot of youngsters," he remarked. "They'll make good soldiers." "That's just what he was, the little runt, and we had the devil's own time finding him. What in Sam Hill did the Captain take him for, I'd like to know? Co. Q aint no nursery. Well, the bugler up at Brigade Headquarters blowed some sort of a call, and Skidmore wanted to know what it meant. They told him that it was an order for the youngest man in each company to come up there and get some milk for his coffee tomorrow morning, and butter for his bread. There was only enough issued for the youngest boys, and if he wanted his share he'd have to get a big hustle on him, for the feller whose nose he'd put out o' joint 'd try hard to get there ahead o' him, and get his share. So Skidmore went off at a dead run toward the sound of the bugle, with the boys looking after him and snickering. But he didn't come back at roll-call, nor at tattoo, and the smart Alecks begun to get scared, and abuse each other for setting up a job on a poor, innocent little boy. Osc Brewster and Ol Perry, who had been foremost in the trick had a fight as to which had been to blame. Taps come, and he didn't get back, and then we all became scared. I'd sent Jim Hunter over to Brigade Headquarters to look for him, but he came back, and said they hadn't seen anything of him there. Then I turned out the whole company to look for him. Of course, them too-awfully smart galoots of Co. A had to get very funny over our trouble. They asked why we didn't get the right kind of nurses for our company, that wouldn't let the members stray out of their sight? Why we didn't call the children in when the chickens went to roost, undress 'em, and tuck 'em in their little beds, and sing to 'em after they'd said 'Now I lay me down to sleep?' I stood it all until that big, hulking Pete Nasmith came down with a camp-kettle, which he was making ring like a bell, as he yelled out, 'Child lost! Child lost!' Behind him was Tub Rawlings singing, 'Empty's the cradle, baby's gone.' Then I pulled off my blouse and slung it into my tent, and told 'em there went my chevrons, and I was simply Scott Ralston, and able to lick any man in Co. A. One o' their Lieutenants came out and ordered them back to their quarters, and I deployed the company in a skirmish-line, and started 'em through the brush toward Brigade Headquarters. About three-quarters o' the way Osc Brewster and Ol Perry, when going through a thicket, heard a boy boo-hooing. They made their way to him, and there was little Skidmore sitting on a stump, completely confused and fagged out. He'd lost his way, and the more he tried to find it the worse he got turned around. They called out to him, and he blubbered out: 'Yes, it's me; little Pete Skidmore. Them doddurned fools in my company 've lost me, just as I've bin tellin' 'em right along they would, durn 'em.' Osc and Ol were so tickled at finding him that they gathered him up, and come whooping back to camp, carrying him every step of the way." And the rush stopped. Cadnan waited for a second, but there was no more. "Dara is not to die," he said. Then he saw Orion hanging over him, very low in the windy sky, shaking with frost. His eyes fixed themselves on the constellation, then gradually he became aware of the sides of a cart, of the smell of straw, of the movement of other bodies that sighed and stirred beside him. The physical experience was now complete, and soon the emotional had shaped itself. Memory came, rather sick. He remembered the fight, his terror, the flaming straw, the crowd that constricted and crushed him like a snake. His rage and hate rekindled, but this time without focus—he hated just everyone and everything. He hated the wheels which jolted him, his body because it was bruised, the other bodies round him, the stars that danced above him, those unknown footsteps that tramped beside him on the road. Farewell to Jane and Caroline!" HoME大香蕉色人阁 ENTER NUMBET 0017
Refs
and further readingHOME
Resources
BLTC Research
Liberal Eugenics
Superhappiness?
Utopian Surgery?
Complete Genomics
The End of Suffering
Wirehead Hedonism
The Good Drug Guide
The Abolitionist Project
The Hedonistic Imperative
The Reproductive Revolution
MDMA: Utopian Pharmacology
Transhumanism: Brave New World?
Critique of Aldous Huxley's Brave New World
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