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NEWSBITS
Tiny biological labs on CDs
Nasa is adapting tiny laboratories embedded in compact discs (CDs) to conduct biological tests aboard the International Space Station and to eventually look for life on other planets.
The CDs, with imbedded biological tests, are under evaluation by Nasa scientists, and several academic and industrial partners. The miniature laboratories were adapted to detect life forms and chemicals derived from life. Nasa’s partners are Stanford University, Stanford; Nanogen, Inc; and the University of California.
“This type of technology will enhance the International Space Station capability as a biological laboratory with greatly increased throughput and state-of-the-art techniques,” said G. Scott Hubbard, director of the Nasa Ames Research Centre (ARC), Moffett Field, Calif. “Some day, this technology could allow astronauts or robots to search for life on other planets or moons,” Hubbard said.
To process the CDs, the researchers adapted a suitcase-sized prototype instrument undergoing laboratory trials at ARC. There are two versions of the CDs, which are about the same size as music CDs. One is plastic, similar to a standard CD, and is disposable. The other is made of glass and is reusable.
“These tiny labs on CDs allow you to do thousands of tests of biological samples quickly and in the field,” said Michael Flynn, a scientist at ARC. “On the Space Station, the types of tests you would do are DNA analyses,” Flynn said.
To begin a test, a scientist places a liquid sample into a small opening near the center of the CD. The researcher puts the disc in the prototype machine that spins the CD. Centrifugal force spreads the sample fluid from the center of the CD through tiny, capillary-like pipes and valves towards the outer edges of the disc and several clear observation areas.
During the journey, special dyes in the CD combine with the sample. The dyes glow when exposed to specific proteins and other chemicals, including particular portions of DNA. The instrument shines a specific color light on the specimen, and if it glows in another specific color, the specimen contains the substance the dye was designed to detect. The CD system can even sample water, and the instrument’s software has image analysis capability that can discriminate between cells and debris. A microscope and digital camera built into the prototype instrument take images of the glowing test sample in the clear observation area after the disc stops spinning.
The next step in evaluation of the prototype is to develop more tests to determine how well the device works. Eventually, researchers want to add a multi-disk changer to the instrument, so it can test several CDs. — Dawn ScienceDotcom Report
Iceman mystery solved
Scientists have pinpointed the likely birthplace of Oetzi the famous Iceman.
The ancient hunter probably spent his childhood in what is now the Italian South Tyrol village of Feldthurns.
Evidence suggests his lifelong travels were confined to a 60-kilometre range south-east of where his body was found.
The 5,300-year-old frozen mummy emerged from a melting glacier along the mountainous border between Italy and Austria in 1991.
Scientists have been carrying out detailed studies of how he lived and died ever since.
The latest research, published in the journal Science, looked at isotopes found in the Iceman’s teeth and bones. They were compared with soil and water samples over a wide area of the Alps.
Biominerals from the diet are deposited in the body at different times — in the teeth, for example, during childhood, and in the bones in adult life. This allowed researchers in Australia, the United States and Switzerland to deduce where Oetzi lived at various stages of his life.
The team believes his movements were restricted to a few valleys within 60 kilometres south east of where his body was discovered. He never moved north of this point and probably grew up in the Eisack valley, in the southern Tyrol.
The scientists think Feldthurns is the Iceman’s most likely childhood home: excavations have revealed a standing stone dating back to the Copper Age.
Later on in life, he moved further north to the mountains of lower Vinschgau, before travelling to the Otz valley where he met his death at the age of 46.
Dr Alexander Halliday of the Department of Earth Sciences at RTH Zurich said: “This is the first time that anyone has made a comprehensive study of the migration of a human in the past. — Dawn ScienceDotcom Report
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