Precision Count Beads™…

Are useful for counting absolute cell numbers in a sample of varying volume.

Precision Count Beads™ are designed for counting the absolute number of cells in a complex population and other particles by flow cytometry. The cell count in the original sample can then be back-calculated. Very few flow cytometers are capable this function, so Precision Count Beads™ are helpful for users without this function built into their cytometer.

Precision Count Beads™ are excited by the violet (405nm), blue (488nm), yellow/green (561nm), and red (633nm) lasers, and emit between 400-800 nm. As the beads have a low forward scatter and high side scatter, this must be taken into account when adjusting the voltage of the scatter channels to ensure the beads are on scale. Vortexing the beads prior to use and using “reverse pipetting” are important for delivering aggregate-free, well distributed accurate amounts of beads.

Precision Count Beads™ can work with all kinds of assays including a lyse, no-wash whole blood assay.



As shown in the top left plot, Precision Count Beads™ have a very high 
side scatter profile, so the voltage may need to be adjusted accordingly.