Microdevice for plasma separation from whole human blood

Blood is one of the easiest gateways to assess internal performance of the human body. Blood can be broadly thought as being a complex composition of cells suspended in plasma. Red Blood Cells (RBCs), White blood Cells (WBCs) and platelets occupy a volume of about 45%. The remaining volume is occupied by the liquid portion of blood (plasma), which is straw-yellow in color. Separation of cells from plasma is one of the most basic, essential and vital step in the field of disease diagnostics. The separation is carried out so as to minimize the interference of cells in the process of analyte detection. Conventionally, plasma separation is carried out via centrifugation. Although the process of centrifugation is easy and widely used, the process is tedious, time consuming and involves multiple stages of blood handling. Also, coupling of centrifugation with a lab-on-a-chip device is a non-trivial issue and invalidates the entire testing being completed at the micro-scale. Microfluidic devices have the potential to address these issues in an effective manner.

Developed microdevice(left), flow of blood through microdevice(right)

In this context, we have developed a microdevice enabling blood plasma separation (see figure). The results obtained are extremely encouraging in terms of separation efficiency. Separation efficiency of almost 100% has been achieved with whole (undiluted) blood. Our device avoids clogging of microchannels as the dimensions of the microchannels were kept comparatively large. The developed microdevice has been extensively tested with human blood. Our developed microdevice yields reliable performance for several hours at a stretch without any degradation in performance. Demonstration of best separation efficiency on whole blood, decent yield, elevated microchannel dimensions, clog free operation, minimal time requirement for sample collection with decent yield, hemolysis free sample, small surface area, simple fabrication techniques are the highlights of the developed microdevice. The developed microdevice therefore possesses all the features required from the practical point of view to realize a µ-TAS (micro total analysis system).

References

  1. Tripathi, S., Kumar, Y.V.B., Agrawal, A., Prabhakar, A., and Joshi, S., "Synthesis of bio-physical and geometrical effects for developing a microdevice for plasma separation from whole human blood," Nature Scientific Reports, Vol. 6, 26749, 2016

  2. Tripathi, S., Kumar, Y.V.B., Agrawal, A., "Separation in Microfluidic devices: A case study on hydrodynamic blood plasma separation technique," Annals of INAE (to appear).

  3. Tripathi, S., Kumar, Y.V.B., Prabhakar, A., Joshi, S., and Agrawal, A., "Passive Blood Plasma Separation at Micro-scale: A Review of Design Principles and Microdevices," Journal of Micromechanics and Microengineering, Vol. 25, 083001 (24 pp), 2015 (invited review article)." Annals of INAE (to appear).

  4. Tripathi, S., Kumar, Y.V.B., Prabhakar, A., Joshi, S.S., Agrawal, A., "Performance Study of Microfluidic Device for Blood Plasma Separation – A Designer’s Perspective," Journal of Micromechanics and Microengineering, Vol. 25, 084004 (15 pp), 2015. " Journal of Micromechanics and Microengineering, Vol. 25, 083001 (24 pp), 2015 (invited review article)." Annals of INAE (to appear).

  5. Prabhakar, A., Kumar, Y.V.B., Tripathi, S., Agrawal, A., "A Novel, Compact and Efficient Microchannel Arrangement with Multiple Hydrodynamic effects for Blood Plasma Separation," Microfluidics and Nanofluidics, Vol. 18, pp. 995-1006, 2015.

  6. Tripathi, S., Prabhakar, A., Kumar, N., Singh, S.G., and Agrawal, A., "Blood plasma separation in elevated dimension T-shaped microchannel," Biomedical Microdevices, Vol. 15 (3), pp. 415-425, 2013.