Reacting Molecules and Colloids Electrophoretically

Tech ID: 30613 / UC Case 2019-545-0


Researchers in UCLA's Department of Chemistry and Biochemistry have harnessed gel electrophoresis in order to direct and program controlled collisional reactions between pulse-like bands of molecules and/or colloidal reagent species.


Gel electrophoresis is a common technique used to characterize and separate ionic molecules and colloidal species such as DNA, RNA, and proteins. Specifically, electrophoretic mobility shift assays (EMSAs) utilize gel electrophoresis to provide valuable information on interactions between macromolecules based on differences in the electrophoretic mobilities of bound versus unbound molecules. Relative binding constants of different ligands, orders of reactions, rate constants, and Arrhenius parameters, can also be measured using EMSAs. However, EMSAs are limited in the insights they provide as reactants are typically loaded in the same well; thus, it is difficult to study fast kinetic reactions having short relaxation times.


Researchers in UCLA's Department of Chemistry and Biochemistry have developed a novel gel electrophoretic method called band-collision gel electrophoresis (BCGE) that can be used to study collisional reactions between two or more molecular and/or colloidal reagent species, provided these species have different electrophoretic mobilities in the gel. UCLA researchers have demonstrated that BCGE can be used to create a wide range of reaction types, including complexation, precipitation, acid-base, redox, and ligand-exchange. BCGE can also be used to study irreversible and reversible reactions, requires a low volume of reagents, and allows for the separation of reaction products from unreacted species. The design of the gel can be further optimized to program different sequences of reactions, increasing the complexity of reactions that can be studied using BCGE. Overall, BCGE overcomes the limitations of EMSAs, is more versatile, and provides significant advantages over current non-collisional EMSAs.


  • Programming reactions and reaction sequences between molecular, macromolecular, and colloidal reagent species having differing electrophoretic mobilities


  • Access to a very wide range of time scales for measurements of reaction kinetics 
  • Offers a broader range of reaction types and products formed compared to EMSAs 
    • Precipitation reactions 
    • Acid-base reactions 
    • Redox reactions 
    • Ligand-exchange reactions 
    • Irreversible and reversible reactions 
  • Enables different programmable sequences of reactions to be performed in parallel 
  • Has been demonstrated over a wide range of pH-- in basic, neutral, and acidic buffers 
  • Requires very small reagent quantities and real-time optical detection can be used 
  • Can be performed in a variety of gel materials, including agarose and poly-acrylamide

State Of Development

The method of BCGE has been demonstrated to work in experiments using a variety of charged and neutral dye molecules, charged and neutral biomolecules, charged surfactant molecules, and charged colloidal particles.

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  • Mason, Thomas G.

Other Information


macromolecule, DNA, RNA, protein, gel electrophoresis, colloid, nanoparticle, binding, kinetics, rate constants, electrophoretic mobility shift assay, EMSA, ionic, charge, reaction, chemistry, complex formation, precipitation, acid-base, redox,, ligand-exchange, chemical engineering, nanotechnology

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