Courtesy of ChemoMetec
For those charged with the mundane, yet critical, task of counting mammalian cells, ChemoMetec of Allerod, Denmark, offers a simple alternative to hemacytometers. Unlike some other cell counters that measure particle size, ChemoMetec's NucleoCounter™ system counts cells based on DNA fluorescence.
After harvesting cells as usual, the researcher--using supplied reagents--lyses and dissolves the cells, adjusts the pH, and aspirates the stabilized nuclei into a disposable propidium iodide-lined cassette. The instrument functions as a fluorescent microscope, exciting the sample with green light-emitting diodes and measuring the emitted red fluorescence with a charge-coupled device camera. Cell viability is calculated by comparison with an untreated sample--only dead cells will take up the DNA-intercalating dye. Used cassettes are discarded along with other cell culture waste.
The NucleoCounter offers several perks. First, it is automated and requires neither calibration nor maintenance. Also, says Julia Cino, product manager for New Brunswick Scientific (...