Dr. Kenia Chávez Ramos
Universidad Nacional Autónoma de México, Mexico
Title: Microdevice based on centrifugal effect and bifurcation law for separation of plasma from on-line diluted whole blood
Biography
Biography: Dr. Kenia Chávez Ramos
Abstract
In recent decades, scientific interest in the development of devices capable of performing routine clinical analyzes through the application of standardized traditional laboratory protocols in a miniaturized lab-on-a-chip device has increased. In the present work, an innovative microdevice for the on-line whole blood dilution with a phosphate buffer solution (PBS) and separation of plasma was designed, manufactured, and characterized. The microdevice was constructed with a rectangular cross-section and spiral-shaped microchannels by photolitography and soft litography. Also, the widths of the diluted plasma and the remaining blood outlet microchannels were different to create a difference in the outlet flowrates to facilitate and achieve the plasma separation based on the combination of centrifugal effect (Dean drag force) and bifurcation law (Zweifach-Fung effect). The separation purity (a) under the separation conditions (total flowrates between 25 and 100 µL/min, entrance flowrate ratio PBS/whole blood between 4 and 10, and hematocrit (% HCT) between 3 and 8) were around 100 % for fresh blood samples, while the separation efficiency (β) was between 8 and 13 %. The concentration in the separated diluted plasma was between 0.1 and 0.7 % (v/v) with plasma flowrates between 3 and 7 µL/min, respectively. The quality of the diluted and separated plasma from micordevice was corroborated from a blood sample from a patient diagnosed with rheumatoid arthritis through the quantification of anti-cyclic citrullinated peptides (anti-CCP) antibodies employing a microdevice immunoassay. The developed microdevice has a high potential to be coupled with the on-line detection of biomarkers.