微球层叠微通道用于全血血浆分离

Microchannel with Stacked Microbeads for Separation of Plasma from Whole Blood

设计并制作了一款由两种大小不同微球层叠堆积的微通道与毛细通道阵列组合而成的微流控芯片装置,可以在全血样本流经微通道过程中,通过微球堆积层过滤、吸附其中的细胞组分,快速分离出血浆。采用负压进样方式在微通道中紧密堆积微球,并采用蛋白封闭液包被的方法增加微球表面亲水性,在毛细作用下,芯片烘干冷却后滴入的全血在微通道中前进,进而分离出血浆。测试了直径分别为10、15、20、23和40μm的不同微球对血浆分离速度的影响,当使用直径为10μm的微球堆积通道时,血浆分离速率最快。考察了堆积通道局部加宽设计等对血浆分离的影响,结果表明,相较于长直型通道,局部加宽通道的血浆分离速率大大增加,最快可达0.16μL/min,可在短时间内收集得到足量血浆,满足大多数临床血液检测等相关要求。利用本方法收集的血浆样本在芯片上进行血液凝集实验,可快速分析待测血液血型,具有良好的实际应用价值。

A microfluidic device integrated with a microchannel stacked by two kinds of microbeads with different sizes and a capillary microchannel array was designed and fabricated. When whole blood sample flowed through these channels, blood cells were filtered and adsorbed by the stacked microbeads, and plasma could be separated rapidly. The microbeads were introduced into the channel by negative pressure and thus stacked compactly. Protein blocking solution was used to improve the hydrophilicity of the bead surface. Then the microchip was dried and cooled before 20 μL blood was dropped in the inlet. Driven by capillary force, the blood proceeded in the channel. The influences of microbeads with different sizes and a locally widened microchannel were investigated. Experimental results showed that, when microbeads with 10 μm in diameter were filled in the locally widened microchannel, the separation rate of plasma was the fastest. The collection rate of plasma could reach up to 0.16 μL/min in this case, which could meet the requirement of most clinical applications. On the chip device, collected plasma was used to carry out the agglutination test, and the blood group could be determined quickly, which verified the usefulness of this method.