What membrane dyes can be used to stain cells after they are fixed?

Lipophilic carbocyanine dyes like CellBrite® and CellBrite® NIR Cytoplasmic Membrane Dyes can be used to stain formaldehyde-fixed cells. Fixation with methanol or other solvents is not recommended. Permeabilization with detergents after staining will extract the dyes and alter the staining pattern. However, we’ve seen good results when formaldehyde-fixed cells are permeabilized before staining with CellBrite® dyes (See Tech Tip: Combining Lipophilic Membrane Dyes with Immunofluorescence).

For staining cells fixed with formaldehyde, we strongly recommend our CytoLiner™ Fixed Cell Membrane Stains. These stains are novel lipophilic fluorescent dyes that offer more consistent and robust staining of formaldehyde-fixed cells than our CellBrite® Cytoplasmic Membrane Dyes or other lipophilic dyes. CytoLiner™ stains are also suitable for downstream immunofluorescence staining protocols. Please note, staining with CytoLiner™ Dyes is not compatible with cells fixed using solvents like methanol or acetone, or with paraffin-embedded samples, because these treatments will remove the lipids from cells, which are required for CytoLiner™ staining. For co-staining with antibodies, we recommend staining with CytoLiner™ Dye first, then blocking with 2% fish gelatin in PBS, followed by antibody incubation in the same buffer. Blocking with BSA or serum is not recommended.

GlycoLiner™, CellBrite® Fix, MemBrite® Fix, and CellBrite® Steady cannot be used to stain the plasma membrane of fixed samples; these dyes will primarily stain intracellular structures in cells that are already fixed.

To find the right dye for your workflow, see our Comparison of Membrane & Cell Surface Stains, or download our Membrane & Surface Stains Brochure.