Blood Cell-free Plasma Separated from Blood Samples with a Cascading Weir-type Microfilter Using Dead-end Filtration

Ching-Chou Wu ； Ling-Zong Hong ； Chun-Ting Ou

《Journal of Medical and Biological Engineering》 32卷3期 (2012/06) Pp. 163-168

並列摘要

Separating plasma from blood samples, which is done to prevent red blood cells (RBCs) and hemoglobin from interfering with measurements, is important for blood analysis. In this study, a weir-type microfilter is constructed for separating plasma in capillarity-driven dead-end filtration. Microfilters containing alternating pores and chambers are fabricated with the help of polydimethylsiloxane replicas, which are cast from a photolithographically micromachined master mold. Master molds with three-dimensional features are created via a two-step procedure using SU-8 3000 series negative photoresist. Microfilters with 6-μm-high pores and 100-μm-deep chambers exhibited the best efficiency of plasma separation from whole blood samples with a 20% or lower concentration. The chambers and pores, whose dimensions are larger than those of RBCs, gradually remove RBCs from blood samples by gravity action. This approach can eliminate the clogging of pores. The isolated plasma exhibits little hemolysis, with an index of hemolysis of about 0.09% as calculated using blood hydrodynamics. The cascading weir-type microfilters passively separate plasma and can be easily integrated with an electrochemical-microsensor-containing substrate for in situ on-chip blood analysis.

並列關鍵字

Plasma ； Separation ； Dead-end ； Filtration ； Capillarity ； Hemolysis