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MemBrite® Fix Cell Surface Staining Kits

Wide choice of dye colors for covalent staining the surface of live cells to conveniently visualize cell boundaries in immunofluorescence experiments.

Product Attributes

Probe cellular localization

Membrane/cell surface, Membrane/vesicular

Cell permeability

Membrane impermeant

For live or fixed cells

Covalent & fixable stains, For live/intact cells

Assay type/options

Co-cultures, Long term staining (24-72h)


Blue, Green, Red, Far-red, Near-infrared

Fixation options

Fix after staining (formaldehyde), Fix after staining (methanol), Permeabilize after staining

Catalog #
100 labelings
500 labelings
Clear selection
(Please select quantity above )

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Product Description

MemBrite® Fix Cell Surface Staining Kits provide a convenient way to visualize cell boundaries in multicolor staining experiments. Staining is rapid and uniform, with a wide choice of colors. MemBrite® Fix dyes covalently label the surface of live cells. The staining withstands fixation and permeabilization for subsequent immunofluorescence staining.

  • Rapid, uniform live cell surface staining
  • Covalent labeling can be fixed & permeabilized for IF staining
  • Stain mammalian cells, yeast, or gram-positive bacteria
  • Choose from 12 bright & photostable dye colors from blue to near-IR
  • Dye options for super-resolution and other specialized imaging applications
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Fixable Cell Surface Stains

MemBrite® Fix Stains are novel reactive fluorescent dye stains that react irreversibly with cell surface proteins, for staining that can withstand formaldehyde or alcohol fixation, and detergent permeabilization. Unlike lectins such as WGA, which bind specific targets that may vary between cell types, MemBrite® Fix dyes react widely with cell surface proteins. MemBrite® Fix staining is rapid and non-toxic to cells, and because MemBrite® Fix dyes are highly water soluble, they stain cells much more evenly than traditional lipophilic membrane dyes like DiO, DiI, PKH, Vybrant®, or CellMask™.

MemBrite® Fix staining kits also can be used to stain yeast and gram-positive bacteria, but not gram-negative bacteria. See our Cellular Stains Table for more information on how our dyes stain various organisms. MemBrite® Fix 405/430 has been validated for staining of extracellular vesicles (EVs) and exosomes.

MemBrite® Fix Staining Kits belong to Biotium’s line of novel cell surface stains that include CellBrite® Fix Membrane Stains. CellBrite® Fix Membrane Stains are fluorogenic dyes that rapidly accumulate in the plasma membrane, where they react covalently with the cell surface. CellBrite® Fix stains require only a single staining step compared to MemBrite® Fix staining, which is a two-step protocol. On the other hand, MemBrite® Fix dyes are available with a wider selection of colors. MemBrite® dyes do not associate with lipids in membranes, and consequently have lower cytoplasmic background after detergent permeabilization compared to CellBrite® Fix.

Selecting a MemBrite® Fix Dye

Several MemBrite® Fix dyes have been validated in super-resolution imaging applications or 2-photon microscopy. MemBrite® Fix-ST dyes are recommended for super-resolution imaging by STORM. MemBrite® Fix or MemBrite® Fix-ST dyes can be used for standard microscopy applications; however, MemBrite® Fix dyes are generally more photostable than MemBrite® Fix-ST dyes. See the MemBrite® Fix Product Table below for details.

Tips for Success

Note that MemBrite® Fix dye stain dead cell more intensely than live cells. With prolonged dye incubation, or if cells are cultured after staining, the dye also will be internalized by endocytosis, resulting in labeling of intracellular vesicles. Please see our Tech Tip: Five Steps for Success with Membrane and Surface Stains for tips on staining and imaging (step 5) with MemBrite® Fix.

Find the Right Stain for Your Application

MemBrite® Fix dyes must be used to stain live cells before fixation. They cannot be used to stain cells that are already fixed (the dyes primarily label intracellular membranes in fixed cells). Our original CellBrite® Cytoplasmic Membrane Dyes can be used to stain cells after fixation and permeabilization, see our Tech Tip: Combining Lipophilic Membrane Dyes with Immunofluorescence. To find the right stain for your application, see our Membrane & Cell Surface Stains Comparison, or download our Membrane & Surface Stains Brochure.

MemBrite® Fix dyes are designed to be fixed shortly after staining. With prolonged dye incubation, or if cells are cultured after staining, the dyes will be internalized by endocytosis, resulting in labeling of intracellular vesicles. By 24 hours after staining, most of the dye will be localized inside the cell, not on the cell surface. For long-term visualization of cell boundaries in culture, we recommend our CellBrite® Steady Membrane Staining Kits. These kits include unique fluorescent membrane probes that retain cell surface staining in live cell cultures for 24 hours or longer. The kits also include an optional CellBrite® Steady Enhancer solution which masks intracellular signal for even greater specificity of cell boundaries.

MemBrite® Fix Cell Surface Staining Kits

Catalog numberSize1Dye2Spectrally
similar to
30092-T100 reactionsMemBrite® Fix 405/430Alexa Fluor® 405
CellBrite® Blue
exosome staining
30092500 reactions
30093-T100 reactionsMemBrite® Fix 488/515FITC
Alexa Fluor® 488
CellBrite® Green
2-photon microscopy
30093500 reactions
30094-T100 reactionsMemBrite® Fix 543/560TAMRA
Alexa Fluor® 546
CellBrite® Orange
30094500 reactions
30095-T100 reactionsMemBrite® Fix 568/580Alexa Fluor® 568
Rhodamine Red
CellBrite® Orange
30095500 reactions
30096-T100 reactionsMemBrite® Fix 594/615Texas Red®
Alexa Fluor® 594
30096500 reactions
30097-T100 reactionsMemBrite® Fix 640/660Cy®5,
Alexa Fluor® 647
CellBrite® Red
30097500 reactions
30098-T100 reactionsMemBrite® Fix 660/680Alexa Fluor® 660N/A
30098500 reactions
30099-T100 reactionsMemBrite® Fix 680/700Cy®5.5
Alexa Fluor® 680
IRDye® 680LT
CellBrite® NIR 680
Single-molecule imaging
2-photon microscopy
30099500 reactions
30101-T100 reactionsMemBrite® Fix-ST 650/665Cy®5
Alexa Fluor® 647
CellBrite® Red
30101500 reactions
30102-T100 reactionsMemBrite® Fix-ST 667/685Alexa Fluor® 660STORM
30102500 reactions
30103-T100 reactionsMemBrite® Fix-ST 681/698Cy®5.5
Alexa Fluor® 680
IRDye® 680LT
CellBrite® NIR 680
Single-molecule imaging
30103500 reactions
30104-T100 reactionsMemBrite® Fix-ST 755/777Alexa Fluor® 750
DyLight® 750
30104500 reactions
FLImP: Fluorophore localization imaging with photobleaching; SIM: Structured illumination microscopy; STED: Stimulated emission depletion; STORM: Stochastical optical reconstruction microscopy; TIRF: Total internal reflection fluorescence

1. Kit size based on 200 uL reaction volume, actual number of reactions will depends on staining volume used.
2. MemBrite™ Fix dyes are named for their Abs/Em maxima. Download the Product Information Sheet for spectra.
3. MemBrite® Fix-ST 681/698 dye is reported to have better performance in STORM imaging than MemBrite® Fix 680/700 dye.

Alexa Fluor & Texas Red are registered trademarks of Thermo Fisher Scientific; Cy Dye is a registered trademark of Cytiva; IRDye is a registered trademark of LI-COR Bioscience.
Vybrant is a registered trademark and CellMask is a trademark of Thermo Fisher Scientific.


Download a list of curated CellBrite® and MemBrite® references.


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