ExoBrite™ WGA EV Staining Kits

ExoBrite™ WGA EV Staining Kits were designed to overcome some of the challenges of EV detection, particularly in flow cytometry. ExoBrite™ WGA EV Stains bind to molecules in the EV membrane for bright, specific staining, with little background.

ExoBrite™ WGA EV Stains are uniquely formulated conjugates of wheat germ agglutinin (WGA), a carbohydrate-binding lectin with high affinity for N-acetylglucosamine moieties of glycoproteins. WGA conjugates are often used for labeling cell membranes as well as gram-positive bacteria. WGA conjugates have also been used to detect EVs due to the presence of glycoproteins on EV membranes.

ExoBrite™ WGA EV Stains were designed to overcome some of the challenges of detecting isolated EVs, particularly in flow cytometry. For example, tetraspanin antibodies commonly used to stain EVs can have varying signal and coverage depending on the EV source. Conversely, ExoBrite™ WGA EV Stains show bright staining of EVs derived from a broad range of sources. We tested EVs derived from 9 cell lines and ExoBrite™ WGA EV Stains showed strong staining for all of them. ExoBrite™ WGA EV Stains are less prone to aggregation than hydrophobic membrane dyes and do not bind non-specifically to polystyrene beads, allowing them to be used to stain bead-bound EVs.

EVs are often labeled with fluorescent antibodies targeting one or more of the tetraspanin proteins CD9, CD63, and CD81. ExoBrite™ WGA staining can be combined with antibody staining, for multi-parameter analysis.

Notes:

1. ExoBrite™ WGA EV Stains have been found to label EVs derived from all cell lines tested (see Validated EV Sources below), but may not stain EVs from every source.
2. In our testing, we have found that ExoBrite™ 490/515 dye may bind to streptavidin coated surfaces or beads if free biotin binding sites are not blocked. We recommend performing a biotin blocking step after binding your biotinylated capture antibody to streptavidin beads or surfaces when using ExoBrite™ 490/515 conjugates. Alternatively, consider using a different ExoBrite™ dye for staining EVs captured on streptavidin beads or surfaces.

ExoBrite™ WGA EV Staining Kits

Validated EV Sources for ExoBrite™ EV Surface Stains

Biotium also offers other validated ExoBrite™ reagents for flow cytometry, western blotting, or super-resolution imaging.

Learn about Biotium’s new ExoBrite™ True EV Membrane Stains. These genuine lipophilic membrane dyes are designed for superior pan-EV labeling over other membrane dyes including PKH, DiO, DiI, and DiD. Biotium also offers ExoBrite™ CTB EV Stains (cholera toxin B conjugates) and ExoBrite™ Annexin EV Stains optimized for bright and sensitive staining of EVs. The ExoBrite™ EV Surface Stain Sampler Kit contains each of Biotium’s ExoBrite™ EV Surface Stains (CTB, WGA, and Annexin V) for assessing which stain offers the best coverage for the EV samples of interest. Biotium also offers ExoBrite™ Antibody Conjugates for optimal detection of CD9, CD63, and CD81 EV markers by flow cytometry and western blotting. For super-resolution imaging by STORM, learn about our ExoBrite™ STORM CTB EV Staining Kits available in four CF® Dyes validated for STORM.