Posted by: Footler PJ29 JUL 2008
Machines that monitor blood pressure, cholesterol levels and the amountof carbon monoxide in a smoker’s breath are, along with the occasionalvisit from an itinerant computer software installer, the nearest thatmost of us will ever get to the white heat of technology. However,scientific instruments are often fascinating, so here are a few newgadgets we will probably never get to use.
Laser tweezers can be used to handle individual strands of DNA. Thetool can grip, manipulate and release DNA and even insert singlestrands into cells. This “optical trapping” has been used in a widerange of experiments.
Jaclyn Nascimento and her team at the University of California inSan Diego collected sperm from various species of primates. Light fromthe laser tweezer held the sperm in place until they moved withsufficient force to break free and go forward.
The experiment showed that sperm from chimpanzees and rhesus monkeysmove faster and with greater force than that of humans or gorillas. Itwas suggested that this difference evolved as a result of competitionbecause the chimps and monkeys are much more promiscuous than humansand gorillas. “The first one to get to the egg succeeds.”
And how about a “virtual colonoscopy”? The usual screening processinvolves passing a fibre-optic camera through the anus to look forpolyps. This can be uncomfortable and may deter those who mightpotentially benefit. A new idea uses a computer tomography scanner tobuild a 3D picture of the colon. However, the colon still needs to becleaned out first.
Now even that irrigation can be done virtually. The patient ingestsa barium sulphate meal to form a strong contrast between faecal matterand body tissues. The new system automatically masks the faecal matterleaving a clear image of the colon.
New Scientist recently reported on a device that can filter outcells that may cause the spread of cancer and may be difficult toisolate from the thousands of normal cells in a sample.
Robert Austin and colleagues at Princeton and Boston University,Massachusetts, are developing a silicon wafer studded with rows of tinypillars through which a stream of cells in a liquid can be directed,focused and separated according to size. Any abnormal cells can then beinvestigated further. The analogy given is that of light passingthrough a prism and splitting into different colours by wavelength.