Lab-on-CD microfluidic platform for rapid separation and mixing of plasma from whole blood

Traditional clinical methods for separating whole blood into blood cells and cell-free plasma are labor intensive and time consuming. Accordingly, the present study proposes a simple compact disk (CD) microfluidic platform for the rapid separation of plasma from whole human blood and the subsequent mixing of the plasma with a suitable reagent. The performance of three CD microfluidic platforms incorporating square-wave mixing channels with different widths is evaluated both numerically and experimentally. The results show that given an appropriate specification of the microchannel geometry and a CD rotation speed of 2000 rpm, a separation efficiency of 95 % can be achieved within 5 ~ 6 s given a diluted blood sample with a hematocrit concentration of 6 %. Moreover, a mixing efficiency of more than 96 % can be obtained within 5 s given a CD rotation speed of 2200 rpm. The practical feasibility of the proposed device is demonstrated by performing a prothrombin time (PT) test. It is shown that while the time required to perform the PT test using a conventional bench top system is around 15 min, the proposed CD microfluidic platform allows the test to be completed within 1 min.