Separation and detection of urinary proteins by two-dimensional electrophoresis on the microfluidic chip

Abstract

A novel separating and detecting method of urinary proteins by non-gel sieving electrophoresis-free flow electrophoresis on the microfluidic chip was proposed in this article. Human serum albumin and human transferrin labeled by fluorescein isothiocyanate were mixed and taken as the synthesized urinary protein samples. Factors affected on separation, such as the rate of electric fields applied in two dimension, the addition in the buffer, the concentration, and pH of buffer, were optimized, that is, 10% (w/v) dextran, 0.5% ethanediamine, 0.2 mol L 21 Tris-boric acid, pH 9.3, the ratio of the applied electric field in two dimensions 1:4.8, respectively. Fluorescein isothiocyanate-human serum albumin and fluorescein isothiocyanate-transferrin were efficiently separated in 2 min, and the resolution of two proteins achieved was 2.2 by the designed microfluidic chip. Then, the urine samples of nephropathy patient were analyzed by the proposed nongel sieving electrophoresis-free flow electrophoresis on the microfluidic chip. The results matched well with those detected by common clinical methods.

A rapid, maskless 3D prototyping for fabrication of capillary circuits: Toward urinary protein detection

“…The microfluidic and lab‐on‐a‐chip systems emerge, offering healthcare accessibility and affordability, quick results, timely management, and improved efficiency . Electrochemical sensing and electrophoretic detection have been widely used for detection of urinary protein. However, these methods require bulky facilities ( i.e ., power supply, amplifier), which limit the devices’ miniaturization and portability.…”