Rose Bengal

Definition

A xanthene-derived fluorescent stain (4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein) that selectively binds to dead or damaged cells with compromised membrane integrity, appearing bright pink to red under visible light. The stain is excluded by intact cell membranes but penetrates cells with disrupted membranes, making it valuable for viability assays and differential staining in biological specimens.

Etymology

Example

In soil microarthropod extraction, Rose Bengal can be added to Berlese funnel or Tullgren funnel preservative fluids to differentially stain dead specimens, allowing researchers to distinguish between organisms killed by the extraction process versus those already dead in the sample; similarly, acarologists use it to assess mite viability in ecological surveys.

Synonyms

• 4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein

Related Terms

• fluorescein
• vital stain
• supravital stain
• Trypan Blue
• neutral red
• Berlese funnel
• Tullgren funnel
• live/dead assay

Usage Notes

Distinguish from true vital stains that enter living cells; Rose Bengal is excluded by intact membranes and thus functions as a supravital or cytotoxicity indicator. The sodium salt is water-soluble and most commonly used. Concentration and exposure time must be optimized for each taxon, as arthropod cuticle and gut contents may nonspecifically bind the dye. Not to be confused with Bengal Rose, a horticultural cultivar.