CellBrite™ Cytoplasmic Membrane Stains
CellBrite™ and CellBrite™ Fix dyes are designed to label cell membranes. Original CellBrite™ dyes contain lipophilic carbocyanine dyes (DiB, Neuro-DiO, DiI, or DiD). These dyes accumulate in membrane lipids where they become fluorescent. Like other membrane dyes like VyBrant® DiO, VyBrant® DiI, ViBrant® DiR, CellMask™, CellVue® Claret, or PKH dyes, original CellBrite™ dyes can be fixed with formaldehyde, but are poorly retained after permeabilization with detergents or fixation with alcohol. CellBrite™ NIR dyes are CellBrite™ dyes with near-infrared fluorescence compatible with small animal NIR imaging systems.
CellBrite™ Fix dyes are a novel class of dye for labeling the cell surface. They are fluorogenic dyes that rapidly accumulate in the plasma membrane, where they react covalently with the cell surface. As a result, surface staining is well-retained after permeabilization or methanol fixation, with only a slight increase in intracellular fluorescence compared to formaldehyde fixation alone. CellBrite™ Fix dyes have better water solubility than classic lipophilic dyes, and as a result they yield much more uniform staining compared to lipophilic carbocyanine dyes like DiO and DiI. CellBrite™ Fix dyes are non-toxic and do not readily transfer between cells. They also can be used to stain yeast and bacteria (gram-positive or gram-negative).
Vybrant® and CellMask™ are trademarks of Thermo Fisher Scientific. CellVue® is a registered trademark of Millipore Sigma.
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™ Fix Membrane Stains are fluorogenic membrane dyes that react covalently with proteins on the cell surface. They have better water solubility than original CellBrite™ dyes and as a result generally give more even staining of the cell surface compared to original CellBrite™ dyes. CellBrite™ Fix are well retained after fixation and permeabiliation or methanol fixation. However, CellBrite™ Fix dyes cannot be used to stain the plasma membrane of cells after they are already fixed (the dyes stain intracellular membranes of fixed cells).
For all membrane stains, if cells are returned to culture after staining, membrane internalization will occur over time, resulting in predominantly intracellular staining.
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. 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. Over time, the dyes will be internalized and become intracellular as membranes turn over. Long term stability of labeling may vary between cell types, depending on rates of membrane turnover or cell division.
CellBrite™ Fix Membrane Stains label the cell surface covalently. Like original CellBrite™ dyes, they are non-toxic and do not readily transfer between cells, but will be internalized and become intracellular as membranes turn over.
Cells can be fixed with formaldehyde after labeling with original CellBrite™ or CellBrite™ NIRhttps://biotium.com/product/cellbrite-nir-cytoplasmic-membrane-dye/ dyes. Lipophilic carbocyanine dyes like the CellBrite™ and CellBrite™ dyes have also been used to stain cells or tissues after formaldehyde fixation. Permeabilization of cells with detergents or solvents, or mounting medium containing glycerol may adversely affect staining. Permeabilization with digitonin (10 ug/mL to 1 mg/mL) has been reported to be compatible with lipophilic carbocyanine dye staining.
CellBrite™ Fix Membrane Stains are a new class of membrane dyes that covalently label the cell surface. They can withstand fixation and permeabilization, or fixation with alcohol after labeling of live cells. CellBrite™ Fix cannot be used to label the plasma membranes of fixed cells or tissues (the dyes label intracellular membranes in fixed cells).
It’s common for DiB Loading Buffer (30024B) to solidify into a gel during storage. This does not affect the product, but the buffer must be in liquid form before use. Heat the solidified gel to 50-60°C for 5-10 minutes and vortex periodically until it has formed a clear liquid. DiB Loading Buffer is viscous, so pipet it slowly to ensure the correct volume is added.
You can heat the DiB Cell Labeling Solution to 37°C for 10 minutes or longer, and pipette the solution up and down or vortex to mix completely until is is completely dissolved.