Microfluidic chip with serially connected filters for improvement of collection efficiency in blood plasma separation

This paper describes a novel microfluidic chip, including implementation of serially connected filters for improvement of collection efficiency in blood plasma separation. We have previously reported on a blood plasma separation device, comprising serially connected filters, and its effect on plasma collection efficiency. This paper describes improvement of the device structure for biological blood separation and integration of the filters into a microfluidic chip. Plasma collection into an outer reservoir enables use of the separated plasma in further processing, although the ultimate objective is on-chip analysis of plasma constituents, this is not currently possible. Thus, a collection mechanism for the serially connected filters was also developed and implemented. The device developed in this study was able to extract approximately 4 μL of plasma from 50 μL of non-diluted whole blood into an outer reservoir without critical hemolysis. The successfully miniaturized filter device was able to collect both plasma and un-separated blood into outer reservoirs for further processing and will be a useful separation platform for μTAS applications.