Washington, Mar 19: Scientists have achieved a major milestone in microfluidics that may soon lead to stand-alone, self-powered chips that would diagnose diseases within minutes.

The device, developed by an international team of researchers from the University of California, Berkeley, Dublin City University in Ireland and Universidad de Valparaíso Chile, is able to process whole blood samples without the use of external tubing and extra components.

The researchers have dubbed the device SIMBAS, which stands for Self-powered Integrated Microfluidic Blood Analysis System.

“The dream of a true lab-on-a-chip has been around for a while, but most systems developed thus far have not been truly autonomous,” said Ivan Dimov, UC Berkeley post-doctoral researcher in bioengineering and co-lead author of the study.

“By the time you add tubing and sample prep setup components required to make previous chips function, they lose their characteristic of being small, portable and cheap. In our device, there are no external connections or tubing required, so this can truly become a point-of-care system,” he said.

For the new SIMBAS biochip, the researchers took advantage of the laws of microscale physics to speed up processes that may take hours or days in a traditional lab. They noted, for example, that the sediment in red wine that usually takes days to years to settle can occur in mere seconds on the microscale.

The SIMBAS biochip uses trenches patterned underneath microfluidic channels that are about the width of a human hair. When whole blood is dropped onto the chip’s inlets, the relatively heavy red and white blood cells settle down into the trenches, separating from the clear blood plasma. The blood moves through the chip in a process called degas-driven flow.

In experiments, the researchers were able to capture more than 99 percent of the blood cells in the trenches and selectively separate plasma using this method.

“This prep work of separating the blood components for analysis is done with gravity, so samples are naturally absorbed and propelled into the chip without the need for external power,” said Dimov.

The team demonstrated the proof-of-concept of SIMBAS by placing into the chip’s inlet a 5-microliter sample of whole blood that contained biotin (vitamin B7) at a concentration of about 1 part per 40 billion.

The findings have been published in the journal Lab on a Chip. (ANI)