Invitrogen CellMask™ Cell Membrane Stain quickly and uniformly labels the membranes of nearly all cell types. The stain works quickly and can be detected with any imaging instrument using standard microscope filter sets. Depending on the cell type and experimental conditions, cell membrane staining will last 60–90 minutes without detectable internalization, providing sufficient time for most studies of live cell dynamics. This stain is fixable but not permeabilizable.

Features of CellMask™ Cell Membrane Stain include:
• Sensitivity—specific and rapid staining of cell membranes
• Excellent retention—staining lasts 60–90 minutes
• Available in Commonly used microscopy channels, green, orange, deep red and near infrared

Disadvantages of other methods
Cell membranes are convenient markers for cell boundaries, so many probes have been used Cell membrane staining. Lipophilic dyes are often used; however, they are rapidly internalized, resulting in a very narrow imaging time window. Fluorescently labeled lectins (such as wheat germ agglutinin) have also been used as cell membrane dyes. Conjugated lectins rely on cell surface sugars for staining, so staining is inconsistent and varies between different cell types. Robust cell membrane staining is important for a variety of applications including translocation assays and membrane dynamics, and can be used as a versatile cell identification tool in traditional and automated imaging and analysis.

How CellMask™ Cell Membrane Stain works
CellMask™ Cell Membrane Stain is designed to uniformly stain the cell membranes of a variety of mammalian cell types and is compatible with DiI, DiO Compared with traditional methods such as labeled wheat germ agglutinin, its internalization is slower.

CellMask™ Cell Membrane Stain is an amphiphilic molecule containing lipophilic groups for excellent membrane loading and a negatively charged hydrophilic dye to anchor the probe to the cell membrane middle). While CellMask™ cell membrane stains provide ample opportunities for live cell imaging, the staining pattern is maintained after formaldehyde fixation, supporting additional multi-parametric imaging options. However, cell membrane staining with CellMask™ does not allow detergent extraction and therefore cannot be used with probes that require permeabilization.