Vybrant Apoptosis Assay kits offer quick and convenient cell staining dye-based methodologies for differentiating apoptotic and necrotic versus healthy cells, which can then be visualized using flow cytometry.

The Vybrant Apoptosis Assay Kit #4 detects apoptosis via changes that occur in cell membrane permeability. This kit contains ready-to-use solutions of both YO-PRO-1 and propidium iodide (PI) nucleic acid stains. YO-PRO-1 stain selectively passes through the plasma membranes of apoptotic cells and labels them with moderate green fluorescence. Necrotic cells are stained fluorescent red with PI.

The Vybrant Apoptosis Assay Kit #5, or the Chromatin Condensation/Dead Cell Apoptosis Kit with Hoechst 33342 and PI for Flow Cytometry, provides a rapid and convenient assay for apoptosis based on fluorescence detection of the compacted state of the chromatin in apoptotic cells. This kit contains ready-to-use solutions of blue-fluorescent Hoechst 33342 dye, which stains the condensed chromatin of apoptotic cells more brightly than the chromatin of non-apoptotic cells, and red-fluorescent PI dye, which stains dead cells.

The Vybrant Apoptosis Assay Kit #6 provides a rapid and convenient assay for apoptosis, using the bright, blue-fluorescent Alexa Fluor 350 conjugate of streptavidin in conjunction with biotin-X annexin V to detect apoptotic cell populations either by flow cytometry or imaging. In addition, the kit includes a ready-to-use solution of the fluorescent red PI nucleic acid–binding dye. PI is impermeant to live cells and apoptotic cells, but stains dead cells with red fluorescence, binding tightly to their nucleic acid. The kit contains an ample amount of each reagent for about 50 flow cytometric assays.