The fascination of the latest scientific gadget

Machines that monitor blood pressure, cholesterol levels and the amount of carbon monoxide in a smoker’s breath are, along with the occasional visit from an itinerant computer software installer, the nearest that most of us will ever get to the white heat of technology. However, scientific instruments are often fascinating, so here are a few new gadgets we will probably never get to use.

Laser tweezers can be used to handle individual strands of DNA. The tool can grip, manipulate and release DNA and even insert single strands into cells. This “optical trapping” has been used in a wide range of experiments.

Jaclyn Nascimento and her team at the University of California in San Diego collected sperm from various species of primates. Light from the laser tweezer held the sperm in place until they moved with sufficient force to break free and go forward.

The experiment showed that sperm from chimpanzees and rhesus monkeys move faster and with greater force than that of humans or gorillas. It was suggested that this difference evolved as a result of competition because the chimps and monkeys are much more promiscuous than humans and gorillas. “The first one to get to the egg succeeds.”

And how about a “virtual colonoscopy”? The usual screening process involves passing a fibre-optic camera through the anus to look for polyps. This can be uncomfortable and may deter those who might potentially benefit. A new idea uses a computer tomography scanner to build a 3D picture of the colon. However, the colon still needs to be cleaned out first.

Now even that irrigation can be done virtually. The patient ingests a barium sulphate meal to form a strong contrast between faecal matter and body tissues. The new system automatically masks the faecal matter leaving a clear image of the colon.

New Scientist recently reported on a device that can filter out cells that may cause the spread of cancer and may be difficult to isolate 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 tiny pillars through which a stream of cells in a liquid can be directed, focused and separated according to size. Any abnormal cells can then be investigated further. The analogy given is that of light passing through a prism and splitting into different colours by wavelength.