AO/PI Staining Solution

AO/PI Staining Solution contains two types of fluorescent DNA dyes: acridine orange (AO) and propidium iodide (PI). AO is able to penetrate intact cell membranes, embed in the nuclei of all cells (including live and dead cells), and emit green fluorescence; PI, on the other hand, can only penetrate incomplete cell membranes and therefore can only be embedded in the nucleus of dead cells, emitting red fluorescence.

This staining solution is optimized for cell counting. Traditional trypan blue staining is not very specific and will also count cell debris or residual red blood cells in PMBCs, resulting in inaccurate counting results. Both AO and PI in this reagent are DNA dyes, which can effectively exclude impurities and red blood cell interference, resulting in accurate sample counting.

Figure 1: The effect of this reagent on cell counting