Thermal Gel Electrophoresis to Streamline Biological Characterizations

Gel electrophoresis is a ubiquitous bioanalytical technique used to screen for proteins or nucleic acids in biological samples. Previous work has transitioned these electrophoretic separations from bulk slab gels into microfluidic systems, resulting in numerous benefits including faster analysis times and lower sample volume requirements. The work presented here describes the development of a versatile system to further enhance the analytical performance of microfluidic gel separations. Temperature-responsive polymers were employed as gel separation matrices because of their unique ability to change viscosity as a function of temperature. Incorporating a thermal dimension into the separation space provided an additional adjustable parameter to tune analytical performance. For example, maintaining distinct temperature regions across a microfluidic device enabled cells to flow through liquid-phase gel but enrich at a solidified gel barrier for analysis. Also, inline analyses were developed to preconcentrate and separate nucleic acids or proteins within a gel for high-sensitivity detection. The flexibility of thermal gels to characterize diverse analytes demonstrates their broad applicability for numerous bioanalytical measurements.