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.
Unique kits allow you to conveniently image cell boundaries
Rapid, uniform live cell surface staining
Covalent labeling can be fixed & permeabilized for IF staining
Stain yeast and gram-positive bacteria
Choose from eight bright & photostable dye colors from blue to near-IR
MemBrite™ Fix Cell Surface Staining Kits are designed for covalently staining the surface of live cells to conveniently visualize cell boundaries in immunofluorescence experiments. Traditional membrane dyes like DiO, DiI, PKH, Vybrant®, and CellMask™ are lipophilic dyes that incorporate into cell membranes. They tend to label cells unevenly due to their low solubility, and they cannot withstand detergent permeabilization or alcohol fixation. MemBrite™ Fix are new covalent cell surface 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 lipophilic membrane dyes. MemBrite™ Fix staining kits also can be used to stain yeast and gram-positive bacteria, but not gram-negative bacteria.
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.
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.
CellBrite™ Cytoplasmic Membrane Labeling Kits are designed to label cell cytoplasmic membranes with fluorescent dyes, available in blue, green, orange, and red. The labeling is stable and nontoxic, suitable for long-term tracking of cells.
CellBrite™ Fix Membrane Stains are a new class of fluorogenic membrane dyes that covalently stain the plasma membrane in live cells. They are unique among membrane stains in that they can withstand both fixation and detergent permeabilization. Available with green, red, and far-red fluorescence.
Biotium’s CellBrite™ NIR Cytoplasmic Membrane Dyes are ready-to-use dye delivery solutions that can be added directly to normal culture media to uniformly label cells in suspension or adherent cultures.
Paraformaldehyde, 4% in PBS is a ready-to-use fixation solution for cells or tissues. It is electron microscopy-grade paraformaldehyde dissolved in pH 7.4 PBS, and is stabilized by packaging under argon with no methanol added.
CellBrite™ Cytoplasmic Membrane Stains are lipophilic dyes for simple, non-toxic, stable labeling of membranes in live or fixed cells. Cells can be fixed with formaldehyde before or after CellBrite™ staining. But the staining has poor tolerance for permeabilization or methanol fixation, so CellBrite™ staining is not easily combined with intracellular immunofluorescence (IF) staining. The dyes also do not stain bacteria or yeast. CellBrite™ NIR dyes are CellBrite™ dyes with near-infrared fluorescence compatible with small animal NIR imaging systems.
CellBrite™ Fix and MemBrite™ Fix stains were developed to overcome some of these shortcomings. They are novel covalent stains that can be fixed and permeabilized for IF staining. CellBrite™ Fix Membrane Stains are fluorogenic reactive membrane dyes that rapidly accumulate at the plasma membrane. When they incorporate into lipids, they become fluorescent, and at the same time react covalently with membrane proteins for stable labeling. Staining takes only 15 minutes in a single step with no wash. CellBrite™ Fix stains mammalian cells, yeast, and bacteria.
MemBrite™ Fix Cell Surface Stains do not bind lipids, but label cell surface proteins. MemBrite™ Fix requires a two-step staining protocol with washing, but offers a more extensive choice of dye colors than CellBrite™ Fix. MemBrite™ Fix also can be used to stain yeast. But unlike original CellBrite™ dyes and lectins, CellBrite™ Fix and MemBrite™ Fix cannot be used on cells that are already fixed.
Original CellBrite™ Cytoplasmic Membrane Stains are lipophilic carbocyanine dyes. These dyes undergo an increase in fluorescence when they insert into lipid bilayers. Lipophilic carbocyanine dyes stably label the plasma membrane and other intracellular membranes of cells. They also can be used to stain fixed cells or artificial lipid bilayers. CellBrite™ cytoplasmic membrane stains are lipophilic carbocyanine dyes. These dyes undergo an increase in fluorescence when they insert into lipid bilayers. Lipophilic carbocyanine dyes stably label the plasma membrane and other intracellular membranes of cells. They also can be used to stain artificial lipid bilayers. Immediately after staining cultured cells, the dyes primarily localize to the plasma membrane. If cells are cultured over time after staining, the labeled membranes are internalized and staining gradually becomes mostly intracellular.
Lipophilic carbocyanine dyes like our original CellBrite™ Cytoplasmic Membrane Stains have been used to stain neuronal cells in culture for several weeks, and in vivo for up to a year (see note below). The dyes do not appreciably affect cell viability, and do not readily transfer between cells with intact membranes, allowing cell migration and tracking studies in mixed populations. Staining with the covalent stains CellBrite™ Fix and MemBrite™ Fix lasts up to 48 hours in tissue culture cells (see note below).
Note: Over time, all cell surface stains will be internalized and become intracellular as membranes turn over by endocytosis. The rate of internalization may vary by cell type, rate of membrane turnover, and rate of cell division. In immortalized cells in culture, most of the surface staining becomes internalized over the course of about 24 hours for CellBrite™, CellBrite™ Fix, and MemBrite™ Fix stains.
For an alternative stable and fixable stain for long term cell tracking or tracking cells in mixed cultures, see our ViaFluor® SE Cell Proliferation Dyes. These dyes covalently label intracellular proteins throughout the cell and are non-toxic and fixable.
Shipping & Handling Disclaimer: Shipping and handling methods are calculated based on item temperature storage recommendation. Large, multi-item orders may be assessed additional fees. Shipping to Puerto Rico may be assessed additional fees. A Biotium customer service representative will contact you if additional fees are required. For expedited shipping, please request in the Order Notes section of the checkout page.
Please note that products with recommended storage at 4°C or -20°C may ship at ambient temperature. This will not affect product performance. When you receive the product, place it under the recommended storage conditions.