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YOUNG INVENTORS AWARDS: GOLD AWARD: BIOLOGY Sexy Solution An Indonesian Ph.D. student devises a simple, long-term and cheap way to store organic materials By Becky Gaylord/SYDNEY Issue cover-dated December 21, 2000 THE WIDE GLASS DOORS of the Monash Institute of Reproduction and Development, on the outskirts of Melbourne, swish open automatically when visitors approach. Light fills the modern building, flooding in through big round windows and down wide hallways. Labs at the institute, sleek with stainless steel, are sites of pioneering work in hi-tech, expensive genetics and molecular biology. But on the third floor, one young scientist's discovery is being hailed as revolutionary--precisely because it's low-tech and cheap. Mulyoto Pangestu, an Indonesian Ph.D. student at the institute, has devised a way to dry and store sperm at room temperature. It costs less than 50 Australian cents (26 U.S. cents) a specimen, relies on common materials like plastic straws and aluminium-foil pouches and requires no special handling. Yet the specimens last for years and remain potent. His technique may also have broader applications, providing an alternative to cold storage for any organization that needs to preserve organic materials. To be sure, sperm have been dried, stored at room temperature and used before by other scientists for later fertilization. "But finding this exceedingly cheap way of doing this--that is a big breakthrough," says Jillian Shaw, Pangestu's chief Ph.D. supervisor at the institute. According to Shaw, Pangestu's discovery will be particularly useful for scientists and doctors in developing countries, who often don't have access to the expensive refrigeration equipment and coolant needed to store organic materials using traditional techniques. For example, many refrigeration systems require liquid nitrogen as a coolant. But the equipment necessary to use it is expensive; the tanks alone can cost A$5,000 each. They're also bulky--some are as tall and heavy as a person--and last only five to 10 years before they need replacing. Yet equipment cost, bulk and obsolescence aren't the only problems associated with refrigeration using liquid nitrogen. Another is that researchers must refill the specimen tanks with the coolant at least weekly because the liquid evaporates. The process, however, is so dangerous that the floors of the rooms where the specimen tanks are located must be specially protected so they won't crack if accidentally splashed, since to remain liquid the coolant must be kept colder than minus 196 degrees Celsius. Yet another problem is that protective gear must be used because eyes and skin can freeze instantly if liquid nitrogen is spilled. And finally, it's difficult, cumbersome and dangerous to move the coolant. In fact, most countries prohibit transporting it by road without special trucks or permits. When the dangers and costs associated with traditional cold storage are taken into account, the benefits of room-temperature preservation become clear. But for Pangestu, it wasn't that easy to make it work with sperm. Yes, he already knew from nature that embryos from some animals such as sea monkeys can dry out and still be alive when rehydrated. But sperm? A determined Pangestu willingly failed for nearly six months as he struggled to evaporate water from sperm, rehydrate the cells and fertilize the eggs. As a drying agent, he tried everything from air to alcohol. Eventually, he realized the process had to occur without any oxygen. "After we looked at all aspects," he adds, "we found some windows to jump through." Last year, finally, he jumped through the right one. Now, Pangestu, who already has used his invention to fertilize the eggs of mice and create normal baby mice from sperm he dried and stored for six months, proudly demonstrates his novel technique. First, he coats the inside of a small plastic straw that costs about 10 Australian cents with a sperm solution, using a syringe-like instrument to suck it evenly up the sides. Then he blows compressed nitrogen gas through the straw--the gas being cheaper, easier to obtain and safer to handle than the liquid form. A small tube flowing with nitrogen is inserted into one end of the coated straw, and as the gas blows through the straw, all the oxygen is pushed out. Within a few minutes, the nitrogen dries the solution. (One tank holds enough gas to dry and fill 1,700 coated straws, costing about 2 Australian cents each.) With the nitrogen still flowing through the straw, Pangestu clamps it closed with a heat sealer, the kind that quickly seals plastic sandwich bags. This traps the nitrogen and the dried specimen. To prevent leaks, Pangestu forces a slightly larger straw over the top of the first one and seals the outer straw, too. The double straw set-up can store sperm at room temperature for about a month before oxygen seeps in. Ideally, this kind of storage must be leak-free and long-term. To achieve that, Pangestu tried wrapping the straws with aluminium foil, but oxygen pushed its way in. Then, he purchased a few special airtight containers, but he also kept looking for a solution that didn't require such a high additional cost. Around this time, Pangestu spied in the lab a light foil pouch about 15 centimetres wide and had it analyzed for leaks. He found that specimens, when sealed inside, would last more than a year. He began shutting the thin double straws inside the foil pouches, which each cost about 5 Australian cents, using the same heat sealer he had used to cap the straws. The sealer can also be used to divide one pouch into several compartments, each the width of about two fingers. Each compartment can provide the specimen-filled straws with a safe, nitrogen-filled home. In the Indonesian student's office, foil pouches are strewn casually on the desk. Some are filled with tiny petrie dishes, silica-gel packets and other things that rattle when shaken, demonstrating the other uses Pangestu has found for them. Most of the pouches, manufactured by a small company in Australia called West's Packaging Service, look as if they're made from the material sold in supermarkets to wrap leftovers. Another is a heavy-duty, dark-green pouch for military rations. This one is labelled "savoury steak fingers"; it's so thick it apparently doesn't leak at all and cells stored in it might last a lifetime. A patent for Pangestu's invention is now pending. "The storage and the drying methods both add to the efficiency," says Ph.D. supervisor Shaw. "It's so cheap, and yet no one had used it." A soft-spoken man in his mid-30s, Pangestu himself grew up in Central Java, and later studied at Jenderal Soedirman University in Purwokerto, where he focused on animal husbandry. When he finished his degree, he remained to teach. A scholarship from the Australian government enabled him to obtain a master's degree in reproductive science that he completed at Monash in 1995. Then he returned to Indonesia to teach at Jenderal Soedirman again. Two years ago, after receiving an Asian Development Bank scholarship, he, his wife and son returned to Australia, so he could study for his Ph.D. Today, Pangestu is eager to develop research products that are accessible to scientists and doctors in his homeland, though his simple procedure can be reproduced in almost any lab in the world. His methods, to be published next year, can also be used by scientists on field trips who need to collect and preserve specimens. "That's the idea," explains Pangestu. "You can use it in the field." Next, he plans to tackle preserving and storing other cells, besides sperm, cheaply and easily. "It is likely that his work will revolutionize the preservation of cells and tissues," says Shaw, who adds that the technique should hold significant interest for organizations that store cells and tissues for research, pathology and clinical medicine. Yet perfecting methods for preserving and storing cells other than sperm will take much work, as most cells are more complicated to dry and rehydrate than sperm, which are among the most compact and stable cells in the body. However, Pangestu has already had some promising results and hopes to do more before his scholarship and student visa run out next year. After that, he says, he might return to Indonesia. Wherever he goes, Pangestu wants to continue the research and see
it used by others. "I hope I can do something more." No ResultsPlease supply at least one search term. Advertise on feer.com and in FEER |
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