A single drop of blood would soon help in testing patients at risk of developing heart disease, according to Dr Shashi K Murthy of the Department of Chemical Engineering at Northeastern University in Boston.

A team of researchers from Harvard and Northeastern universities in Boston have come up with a new credit card-sized device that may help physicians to monitor heart disease and help grow new vascular tissue for transplants.

They showed how this device can measure and collect a type of cells needed to build vascular tissue, called endothelial progenitor cells, using only 200 microlitres of blood.

"This simple device is a promising tool for the paediatric and adult population in detecting, diagnosing, monitoring, and providing the option of treating cardiovascular disease by utilising a small quantity of blood," said Dr Murthy.

The device works similar to Velcro or a magnet. The inside is coated with antibodies that only bind to endothelial progenitor cells. Blood flows through the device through a funnel-like opening and passes over the antibodies, and endothelial progenitor cells are "picked up" in the process.

In addition to allowing researchers to collect cells from a very small amount of blood, the device's design also provides researchers with a new model to study the effects that blood flow in the body has on cell binding (like clots form in arteries).

"Most immediately, this could be a new tool to assess cardiovascular health that cuts the amount of blood needed down to a pin prick. Its compact size might make it an excellent tool for use in developing countries where access to medical laboratories does not exist," said Gerald Weissmann, MD, editor-in-chief of The FASEB Journal.