Cell Counting  > Consumables & Accessories  > Cell Counting Reagents
Propidium Iodide Stain

Propidium iodide is a cell-permeable stain that binds to nucleic acids. Nonviable cells and cells with damaged membranes are the only ones that can take up propidium iodide, since intact membranes cannot penetrate it. Once bound to nucleic acids, its fluorescence is multiplied by 20-30, causing the cell to fluoresce red.

LUNA™ Automated Fluorescence Cell Counters can use propidium iodide stain (F23002) with acridine orange stain (F23002) to assess cell viability. Viable nucleated cells will fluoresce green and non-viable cells will fluoresce red. Due to Förster resonance energy transfer (FRET), the signal from propidium iodide absorbs the signal from acridine orange in non-viable cells, ensuring that double-positive results do not occur.

Compatible Instruments
LUNA-FL™ Automated Cell Counter
LUNA-STEM™ Automated Cell Counter
LUNA-II YF™ Automated Yeast Cell Counter
LUNA-FX7™ Automated Cell Counter


Molecular formulaC27H34I2N4
Molecular weight668.39 g/mol
AppearanceClear liquid
Cell permeabilityMembrane permeant
Excitation/emission493/636 nm (in aqueous solution)
533/617 nm (when bound to nucleic acids)


Ordering Information

Cat #DescriptionQty
F23003Propidium Iodide Stain2 X 0.5ml