Microfluidic disk for the determination of human blood types

We present a novel method to determine human blood types on a centrifugal microfluidic disk. The disk spun on stepping motor features sequential aliquoting structures and receiving chambers where red blood cells coagulate. The bubble-free priming of the receiving chambers is governed by 2-stage centrifugal rotation, including metering fingers in the low frequency and receiving chambers in the high frequency within 1 min. Then the shaking step was added in order to make antigens and antibodies mix until well, which is convenient to detect the occurrence of agglutination. The captured images by a digital camera were analyzed in MATLAB software, achieving the automatic blood type classification of the sample under test. Experimental results showed that the standard deviation correspond to the agglutination is greater than 30 pixels. The proposed strategy can be used to develop devices for determination of human blood types automatically.