Plant Cell Viability Assay Kit, Fluorescent staining system to highlight viable and non-viable cells

Application

Viable cells are living cells with intact plasma membranes. These cells can be distinguished by the presence of intracellular esterase activity. This activity is assayed through the enzymatic hydrolysis of fluorescein diacetate or related compounds, such as carboxyfluorescein or calcein AM. These lipophilic compounds are membrane-permeable and non-fluorescent. In the plant cell, they are hydrolyzed to highly polar fluorescent compounds. Because of their polar nature, these compounds are unable to diffuse across the plasma membrane and are retained within viable cells, producing an intense green fluorescence within the cytoplasm. Fluorescein diacetate was found to be the optimal dye for staining viable plant cells. It does not photobleach as quickly as calcein AM, and produces much less background fluorescence than carboxyfluorescein diacetate in plant cells. Non-viable cells could be either living or dead. They can be distinguished from viable cells by their non-intact or damaged plasma membranes. Propidium iodide and related compounds, such as ethidium homodimers-1 and -III, can only enter cells with damaged membranes, whereupon they intercalate into double-stranded nucleic acids. This results in a bright red fluorescence in non-viable cells, particularly in the nucleus where the concentration of nucleic acids is highest. Propidium iodide is the optimal dye for staining non-viable plant cells. In plant cells it specifically labels nucleic acids, whereas ethidium homodimers-1 and -III both bind non-specifically to the plant cell wall.

General description

The Plant Cell Viability Assay Kit is designed for the differential viability staining of plant cells. The kit employs a dual color fluorescent staining system to highlight viable and non-viable cells. This procedure has been used to stain intact plant tissue, callus tissue, cell suspension culture, and protoplasts.

Other Notes

The components of this kit must be protected from light and stored at -20 °C with desiccant. Propidium iodide is stable in aqueous solution. However, fluorescein diacetate will hydrolyze in aqueous solution. Dilutions of the dyes should be used within one day.