The vacuum seeps capillary blood out of the micropunctures and through the microfluidic channels into a collection chamber filled with prefilled lithium or EDTA. Blood may be transferred to an “analyzer” by placing a precision pipette into a blood access port at the bottom of the device. The device collects up to 100µL of blood.
Another automated capillary device called the Hemolink, which is under development by Tasso, Inc., relies on micro-fluid properties to draw blood from the skin. Once in place on the arm, it takes around two minutes to extract 0.15cc of blood. Further research is underway to ensure that the collected sample will remain viable for a week at 140°F/60°C. The concept is that the device containing the collected blood could be shipped to a distant laboratory for testing.