Are tandem dyes sensitive to fixatives and permeabilization agents?

Yes, tandem dyes are sensitive to fixatives and permeabilization agents.

Fixatives and permeabilization agents such as detergents can have several adverse effects on tandem dyes. They can reduce the brightness of tandem dyes or break the covalent bond between the two dyes in the pair causing the tandem dye to degrade.

If adding a fixative or permeabilization agent is absolutely necessary in your assay, keep the solution as mild as possible and limit the exposure to the shortest time possible to minimize the degradation of the dye. It’s best to avoid storing tandem dyes in fixative for long periods of time as it can increase auto-fluorescence significantly.