Abstract

Background: This paper presents a fundamental study of protein manipulation under the influence of dielectrophoretic (DEP) force for a lab-on-a-chip platform.

Objective: Protein manipulation is dependent on the polarisation factor of protein when exposed to an electric field. Therefore the objective of this work is a microfluidic device and measurement system are used to characterise the human beta-2 microglobulin (β2M) protein via lateral attractive forces and vertical repulsive forces by means of DEP responses.

Method: The manipulation of the β2M protein was conducted using a microfluidic platform with a tapered DEP microelectrode and the protein concentration was quantified based on a biochemical interaction using an Enzyme-Linked Immunosolvent Assay (ELISA). The protein distribution has been analysed based on the β2M concentration for each microfluidic outlet.

Results: At 300 kHz, the protein experienced a negative DEP (nDEP) with of 83.3% protein distribution on the middle microchannel. In contrast, the protein experienced a positive DEP (pDEP) at 1.2 MHz with of 78.7% of protein on the left and right sides of the microchannel.

Conclusion: This is concept proved that the tapered DEP microelectrode is capable of manipulating a β2M via particle polarisation, hence making it suitable to be utilised for purifying proteins in biomedical application.

Keywords: Dielectrophoresis, Beta-2-microglobulin, Lab on chip, artificial kidney, hollow fibre membrane, end-stage renal disease.