The Joy of Counting: A recipe for accurate cell-based assays

Counting cells directly using automated image acquisition and analysis is the most straightforward and accurate method for measuring the size of a cell population. Coupled with powerful Gen5™ software, the Cytation and Lionheart systems deliver intuitive and accurate cell counts using both label-free and fluorescent label-based techniques. Cell counts provide a sensitive metric for cell proliferation and viabilityassays, as well as a powerful method for normalizing results across conditions and replicates.

Quantitative Evaluation of Cell Proliferation Using Label-Free Direct Cell Counting

Label-free methods of measuring cell growth kinetics are preferable over the use of stains that can influence proliferation rates. Although confluence level can be used for some applications, cell counting is the most direct quantitative measure of cell proliferation over a broad range of cell population densities.

High contrast brightfield cell counts over time relative to confluence. A comparison of NIH3T3 direct cell counts and percent confluence over time demonstrate the different characteristics of the two cell growth metrics. Label free cell counts indicate robust logarithmic cell growth up to full confluence (dashed line).

Profiles from 5 drug concentrations demonstrate a cell type-dependent differential dose response. NIH3T3, HeLa and HCT116 cell proliferation profiles enable quantitative analysis of drug response. Cell counts per mm2 were calculated every 2 hours for 5 days or until cells reached full confluence.