| When using the Guava ViaCount reagent
and the Guava PCA™ instrument to count cells, cell
viability is detected by differential permeation of a
DNA intercalating dye. Live cells with intact membranes
exclude this stain, while dead and dying cells
with compromised membrane integrity allow the dye
to penetrate and stain cellular DNA.We have shown
that cells which take up intermediate amounts of the
viability dye in ViaCount also react with Annexin V,
indicating they have entered the apoptotic pathway.
The apoptotic cells are distinguishable from the
healthy live cells and dead cells, and can be readily
quantitated using CytoSoft™ version 2.0. Conventional
methods for counting cells using trypan blue
exclusion do not distinguish apoptotic cells from live
cells. Thus, a more realistic assessment of cell culture
health can be made quickly and easily, while obtaining
cell count and viability data using ViaCount. |
