Plasma separation and preparation on centrifugal microfluidic disk for blood assays

Abstract

The present study proposes a simple lab-on-CD device in which the plasma is first separated from the whole human blood, then divided into two samples of equal volume, and finally decanted into a detection chamber for analysis purposes. The performance of the proposed device is then evaluated using blood samples with hematrocrit concentrations ranging from 6 to 48 %. The results show that for a blood sample with a hematocrit concentration of 6 %, a separation efficiency of 96 % can be achieved within 5---6 s. Moreover, the two plasma samples collected from the left and right branches of the optimized Y-shaped splitter network differ in volume by no more than 0.5 nL. It is shown that the volume of plasma decanted into the detection chamber can be precisely controlled through an appropriate manipulation of the disk rotation speed. Finally, the practical feasibility of the proposed device is demonstrated by performing a creatinine test, the linear dynamic range show that it can be used for creatinine detection in blood assay. In this study, systematical evaluation on the functionality and performance of such a device has been done. The merits of this device are its low cost, straightforward fabrication process, low sample consumption, and high portability.