A simple preparative free‐flow electrophoresis joined with gratis gravity: I. Gas cushion injector and self‐balance collector instead of multiple channel pump

Abstract

This paper describes a novel free-flow electrophoresis (FFE), which is joined with gratis gravity, gas cushion injector (GCI) and self-balance collector instead of multiple channel pump, for the purpose of preparative purification. The FFE was evaluated by systemic experiments. The results manifest that (i) even though one-channel peristaltic pump is used for the driving of background buffer, there is still stable flow in the FFE chamber; (ii) the stable flow is induced by the gravity-induced pressure due to the difference of buffer surfaces in the GCI and self-balance collector; (iii) the pulse flow of background buffer induced by the peristaltic pump is greatly reduced by the GCI with good compressibility of included air; (iv) the FFE can be well used for zone electrophoretic separation of amino acids; (v) up to 20 inlets simultaneous sample injection and up to five to tenfold condensation of amino acid can be achieved by combining the FFE device with the method of moving reaction boundary. To the best of authors' knowledge, FFE has not been used for such separation and condensation of amino acids. The relevant results achieved in the paper have evident significance for the development of preparative FFE.

The protein folding transition state: Insights from kinetics and thermodynamics

“…19,[29][30][31] In general, however, structural reaction coordinates may not necessarily measure how dynamically close one conformation is to the native one ͑i.e., the kinetic progress toward the native state͒. 32 Hence, difficulties in identifying the appropriate reaction͑s͒ coordinate for folding creates an additional challenge for theorists and simulators aiming to study protein folding in light of the TST. 33 Therefore, it may not be straightforward to accurately determine the folding TSE from equilibrium sampling.…”

Lab-scale preparations of Candida albicans and dual Candida albicans–Candida glabrata biofilms on the surface of medical-grade polyvinyl chloride (PVC) perfusion tube using a modified gravity-supported free-flow biofilm incubator (GS-FFBI)

“…As demonstrated previously(Chen et al, 2009), a constant height 320 difference between the medium surface in GCI and those in the four 321 incubators could be maintained during the incubation process, if the 322 whole GS-FFBI was airtight. The formed hydrodynamic pressure 323 would sustain the medium surfaces in the four incubators at the same 324 heights, guaranteeing that the four incubated PVC strips could receive 325 the same quantities of nutrient and flow to produce equivalent biofilms.…”

Preparative free‐flow electrophoresis, a versatile technology complementing gradient centrifugation in the isolation of highly purified cell organelles

“…Main issues for the separation quality during an FFE run are a constant laminar flow not to be disturbed at the sample inlets and outlets. For this reason Chen and colleagues developed an FFE device containing a gas‐cushion injector and a gravity‐induced self‐balance collector . Connecting both devices to the inlets and outlets of the separation chamber, respectively, allowed an equalized buffer flow with minimized pulse of the peristaltic pump by exploiting the accessory gravitational forces in the system (see illustrations in for details).…”

“…For this reason Chen and colleagues developed an FFE device containing a gas‐cushion injector and a gravity‐induced self‐balance collector . Connecting both devices to the inlets and outlets of the separation chamber, respectively, allowed an equalized buffer flow with minimized pulse of the peristaltic pump by exploiting the accessory gravitational forces in the system (see illustrations in for details). Based on this system, the group invented a mid‐scale FFE (7 × 4 cm separation chamber), which requires less buffer and sample flow than the classic FFE systems but still have the potential for extensive analyte sampling, required for a substantial biochemical or cell biological characterization of the samples .…”