New York, Oct 8 (IANS): Researchers have invented a miniature device to test exosomes - minuscule membrane vesicles released from most cells - for an early diagnosis of cancer.

Dubbed the "lab-on-a-chip", the device promises faster result times, reduced costs, minimal sample demands and better sensitivity of analysis when compared with the conventional instruments used to examine these tiny biomarkers.

The discovery could lead to less invasive, earlier detection of cancer and sharply boost patients' odds of survival, researchers noted.

While the average piece of paper is about 100,000 nano-metres thick, exosomes run just 30 to 150 nano-metres in size.

Because of this, exosomes are hard to separate and test.

"A 'lab-on-a-chip' shrinks the pipettes, test tubes and analysis instruments of a modern chemistry lab onto a microchip-sized wafer," said Yong Zeng, assistant professor of chemistry at the University of Kansas in the US.

Essentially, it allows precise manipulation of minuscule fluid volumes down to one trillionth of a litre or less to carry out multiple laboratory functions such as sample purification, running of chemical and biological reactions and analytical measurement.

"Using the lab-on-a-chip, lung cancer could be detected much earlier, using only a small drop of a patient's blood," Zeng stressed.

Beyond lung cancer, Zeng said the lab-on-a-chip could be used to detect a range of potentially deadly forms of cancer.

First described in the mid-'80s, exosomes were once thought to be "cell dust" or trash bags containing unwanted cellular contents.

However, in the past decade, scientists realised that exosomes play important roles in many biological functions.

The paper was published in the Royal Society of Chemistry journal.