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Cell count & viability assay

Detection of total and dead cell populations using fluorescent cytometry

  • Fast and convenient cell count and viability measurement
  • Consistency across instruments, users and sites
  • Objective analysis – no human error in sample preparation
  • Scalable system with 21 CFR Part 11 / GMP-ready software
  • Personal support by our dedicated experts
  • Specialized protocols for mammalian and insect cells
  • Automated PDF reports
  • Export data in FCS/ACS formats (for NC-3000™)
In the Cell Count & Viability Assay, the sample is loaded into a cassette containing AI and DAPI and counted with a NucleoCounter® instrument. In the resulting data image, viable cells are green and non-viable cells are blue.

Overview of the cell count & viability Assay

With the NucleoCounter® family of cell counters, you can count your cells quickly and easily. Our cell counting assays are accurate, precise, and versatile, meeting the needs of even the most specialized cell types and cultures.

We offer several instruments with cell counting assays that are optimized for different applications:

How our cell count & viability Assay works

Our NucleoCounter® instruments use automated fluorescence cytometry to count cells and determine viability. They rely on fluorescent dyes, acridine orange (AO) and 4′,6-diamidino-2-phenylindole (DAPI), to identify live and dead cells and provide accurate cell counts.


AO is a membrane-permeable dye that binds to nucleic acids, staining all the cells in a sample. DAPI cannot penetrate the cell membrane, hence it only stains non-viable cells with a damaged cell membrane. Detecting the signals from these two fluorescent dyes allows us to exclude debris and count cells accurately and consistently, with no subjectivity about what is or is not counted as a cell.

Software images from the Cell Count & Viability Assay. Viable cells are green (stained with AO), while non-viable cells are blue (stained with DAPI).

Trusted by experts

Thanks to their versatility, our cell counting instruments are used by thousands of customers around the globe in a vast range of applications, including cell and gene therapy, therapeutic protein production, vaccine manufacturing, bioprocessing, clean meat, animal reproduction, and research. Some recently published examples include:

  • Researchers at the Jenner Institute used a NucleoCounter® to monitor the cell density of their HEK cells during their adenovirus-vectored vaccine manufacturing processes. Their work was published recently on bioRxiv.
  • Research from Theresienkrankenhaus showed that in patients with osteoarthritis of the knee who received adipogenic stromal-vascular fraction therapy, a greater number of cells (measured with a NucleoCounter®) correlated with better outcomes for patients.
  • The Hackensack University Medical Center used a NucleoCounter® to assess viability of fresh and cryopreserved hematopoietic progenitor cell products before batch release.
  • Scientists at the Autonomous University of Barcelona used a NucleoCounter® to monitor the production of virus-like particles.

You can read more examples of our cell counting assays in action on our case studies page.

The advantages of NucleoCounter® cell counting

Precise, Objective Analysis

Precise, repeatable results mean confidence in your processes, research, and decisions. Our cell counting assays use a comprehensive approach to eliminate human error and guarantee precise, objective cell counting:

  • We use fluorescence microscopy and image analysis to quantify cells automatically. NucleoCounter® instruments used fixed focus and exposure, so no adjustments are required, removing the potential for human error or inter-user variation.
  • All our instruments are calibrated against a reference instrument, ensuring that every machine gives the same result, no matter where they are or who is operating them.
  • Our cassettes are individually volume calibrated to ensure high precision. Furthermore, they contain immobilized cell counting dyes, making staining a closed, standardized process that eliminates pipetting errors.
  • Our software performs a series of analysis checks to ensure optimal sample analysis and will tell you if there are too few or too many cells in the sample to ensure accurate results.

Our instruments, cassettes, and software combine to provide exact cell counting and low coefficients of variation, no matter who does the analysis, where they do it, or which instrument they use. As a result, our NucleoCounter® instruments provide lower variation than other cell counting assays. For example, the NC-202™ typically provides a coefficient of variation below 5%.

Fast & Easy to Use

The user-friendly nature of the NucleoCounter® instruments allows anyone to measure cell viability. There are three simple steps:

  1. Put the cassette into your sample and press the piston
  2. Load the cassette into your NucleoCounter®
  3. Measure the cell count and viability of your sample using our universal cell counting protocol

The results are available within 1 minute. Our accompanying software displays your results and allows you to see the viable and non-viable cells with the click of a button. Your data can be exported to different formats and extracted into PDF reports.

GMP Compliance Made Easy

Our protocols eliminate variability and subjectivity from the cell counting process, ensuring that your results are precise and consistent, no matter who is conducting the count.

What’s more, our simple workflows are ideal for short, easy to understand SOPs. Consequently, validating your cell counting methods for GMP compliance is straightforward and pain-free.

Our NucleoCounter® NC-200™, NC-202™, NC-250™, and NC-3000™ instruments are also Annex-11 and 21 CFR Part 11-ready.

The NC-View™ software is GMP-ready as it supports electronic signatures, adapted protocols, and automated PDF reports

Count all cell types

Our cell counting assays are universal and can count all nucleated cells. As a result, you can use our NucleoCounter® instruments with even the most specialized cell types and culture conditions, including:

How Our Cell Count & Viability Assay Works Natural killer (NK) cells
Leukocytes Insect cells
Chinese hamster ovary (CHO) cells Yeast
Mesenchymal stem cells (MSCs) Whole blood (WBC)
Induced pluripotent stem cells (iPSCs) Stromal vascular fractions
Peripheral blood mononuclear cells (PBMCs) Microcarriers
Hepatocytes Spheroids
T cells Aggregated cells

Quick on-demand support

Our NucleoCounter® instruments all come with access to our scientists and cell counting experts. Our world-class team will support you throughout product installation and protocol development. We also offer training, application support, and dedicated field service teams to ensure you achieve optimal instrument performance and the best quality results.

To learn more about our cell counting solutions, visit our products page or contact us.