Collection of serum albumin aggregate nanoparticles from human plasma by dielectrophoresis.

Dielectrophoresis (DEP) is a fast and reliable nanoparticle recovery method that utilizes nonuniform electric fields to manipulate particles based on their material composition and size, enabling recovery of biologically-derived nanoparticles from plasma for diagnostic applications. When applying DEP to undiluted human plasma, collection of endogenous albumin proteins was observed at electric field gradients much lower than predicted by theory to collect molecular proteins. To understand this collection, nanoparticle tracking analysis of bovine serum albumin (BSA) dissolved in 0.

Impact of buffer composition on biochemical, morphological and mechanical parameters: A tare before dielectrophoretic cell separation and isolation.

Dielectrophoresis (DEP) represents an electrokinetic approach for discriminating and separating suspended cells based on their intrinsic dielectric characteristics without the need for labeling procedure. A good practice, beyond the physical and engineering components, is the selection of a buffer that does not hinder cellular and biochemical parameters as well as cell recovery. In the present work the impact of four buffers on biochemical, morphological, and mechanical parameters was evaluated in two different cancer cell lines (Caco-2 and K562).

Protein Dielectrophoresis: A Tale of Two Clausius-Mossottis-Or Something Else?

Standard DEP theory, based on the Clausius-Mossotti (CM) factor derived from solving the boundary-value problem of macroscopic electrostatics, fails to describe the dielectrophoresis (DEP) data obtained for 22 different globular proteins over the past three decades. The calculated DEP force appears far too small to overcome the dispersive forces associated with Brownian motion. An empirical theory, employing the equivalent of a molecular version of the macroscopic CM-factor, predicts a protein's DEP response from the magnitude of the dielectric -dispersion produced by its relaxing permanent dipole moment.

Protein dielectrophoresis: Key dielectric parameters and evolving theory.

Globular proteins exhibit dielectrophoresis (DEP) responses in experiments where the applied field gradient factor ∇E appears far too small, according to standard DEP theory, to overcome dispersive forces associated with the thermal energy kT of disorder. To address this a DEP force equation is proposed that replaces a previous empirical relationship between the macroscopic and microscopic forms of the Clausius-Mossotti factor. This equation relates the DEP response of a protein directly to the dielectric increment δε and decrement δε that characterize its β-dispersion at radio frequencies, and also indirectly to its intrinsic dipole moment by way of providing a measure of the protein's effective volume.

Protein Dielectrophoresis: I. Status of Experiments and an Empirical Theory.

The dielectrophoresis (DEP) data reported in the literature since 1994 for 22 different globular proteins is examined in detail. Apart from three cases, all of the reported protein DEP experiments employed a gradient field factor ∇Em2 that is much smaller (in some instances by many orders of magnitude) than the ~4 10 V/m required, according to current DEP theory, to overcome the dispersive forces associated with Brownian motion. This failing results from the macroscopic Clausius-Mossotti () factor being restricted to the range 1.