Cation-selective Membranes
Cation-selective Membranes - Related Videos
07:38
Functional Characterization of Na+/H+ Exchangers of Intracellular Compartments Using Proton-killing Selection to Express Them at the Plasma Membrane
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Cited by 4 •
2015
The first part of this article shows how to select mutant cell lines expressing vesicular Na+/H+ exchangers at their plasma membrane. The second part provides protocols based on intracellular pH measurements and fast ion uptake, which are used to determine the ion selectivity and the kinetic parameters of these exchangers.
10:23
Synthesis of Cationized Magnetoferritin for Ultra-fast Magnetization of Cells
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Cited by 1 •
2016
A protocol for the synthesis and cationization of cobalt-doped magnetoferritin is presented, as well as a method to rapidly magnetize stem cells with cationized magnetoferritin.
12:48
Measuring Cation Transport by Na,K- and H,K-ATPase in Xenopus Oocytes by Atomic Absorption Spectrophotometry: An Alternative to Radioisotope Assays
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Cited by 7 •
2013
We describe a method to quantify the activity of K+-countertransporting P-type ATPases by heterologous expression of the enzymes in Xenopus oocytes and measuring Rb+ or Li+ uptake into individual cells by atomic absorption spectrophotometry. The method is a sensitive and safe alternative to radioisotope flux experiments facilitating complex kinetic studies.
04:21
Enhancing Viral Transduction in Natural Killer Cells Using a Cationic Polymer
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2025
This video demonstrates an assay for cationic polymer-mediated viral transduction in natural killer (NK) cells. The cells are incubated with transgenic lentivirus vectors encoding a fluorescent protein. The addition of a cationic polymer enables the virus to attach to the cells and integrate its RNA into the host genome, expressing the fluorescent protein. The fluorescence is quantified to assess the polymer-induced enhancement of transduction.
01:19
Assessing Bacterial Biofilm Formation Using a Cationic Dye-Based Assay
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2026
Begin with a bacterial suspension in nutrient media.Add the suspension to a multi-well plate and incubate.The nutrients in the media facilitate bacterial growth and attachment.The adhered bacteria secrete extracellular polymeric substances consisting of polysaccharides, proteins, and DNA to form a layer of biofilm.Wash multiple times with buffer to remove unbound bacteria.Invert the plate to ensure the removal of residual liquid from the well and allow the biofilm to dry.Treat with a fixative...
FAQs
Fixed charged groups create an electrostatic environment that favors movement of oppositely charged counterions while limiting co-ions with the same charge. This interaction works together with hydrated channels or pores, so transport depends not only on charge but also on how ions interact with the membrane structure. Adjusting these features can help regulate ionic flow in engineered systems.
A concentration gradient provides a driving force for ion movement, but the membrane structure determines how effectively ions can respond to it. Hydrated channels or pores can alter access and movement, while charge interactions favor some ions over others. Consequently, two membranes with similar chemical charges may produce different transport behavior if their internal structures differ.
A cation-selective membrane combines a transport pathway with charge-based exclusion, favoring positively charged ions and restricting anions, neutral species, or larger species. A nonselective pathway would provide less control over which components move. This distinction matters when a system must separate ionic populations or regulate transport rather than simply permit broad molecular passage.
Researchers should consider the fixed charged groups, the arrangement of hydrated channels or pores, concentration gradients, and the size and charge of transported species. These variables jointly influence attraction, exclusion, and mobility. Considering them together helps link membrane composition and structure to the desired transport outcome instead of treating selectivity as a single isolated property.
In bioengineering, these membranes support ion-exchange processes, separation technologies, electrochemical devices, biosensors, and biomimetic systems. Their value comes from controlling which ionic species move through a material and how transport responds to gradients and structure. This control can support designs for molecular delivery, energy conversion, and regulation of physiologically relevant ionic signals.
Biomimetic systems can use selective ionic transport to reproduce aspects of controlled movement found in biological environments. By regulating positively charged ions through membrane pathways, engineers can influence ionic gradients and transport signals. The same principle provides a basis for platforms intended to manage molecular delivery or physiological signal regulation, although performance depends on membrane structure and transport conditions.