Cell Counting: Label-Free
Cell counting is used as a widespread measurement in tissue culture to assess cell density for cell-based assays, as a readout in proliferation, viability and toxicity assays, and to normalize cell-based assay results for differences in cell density.
Most cell counting methods require the presence of a fluorescent nuclear label. Intercalating nuclear stains can alter the native cell properties and limit experiment duration due to cytotoxic effects. An alternative approach requires the difficult and costly endeavor of establishing stable cell lines expressing a fluorescent nuclear marker.
Given these limitations, label-free direct cell counting has considerable advantages over methods that require fluorescent labels. The High Contrast (HC) cell counting application uses modified brightfield imaging to generate a bright point of light for each cell that is easily identified and counted by Gen5™ software without the use of labels.

High contrast brightfield

HC Cell Counting

Overlaid images with object masks

Strong linear correlation with counts derived from nuclear label-based method
Application Notes:
- Label-Free Phenotype MicroArrays™ Analysis of Cellular Energetics and Apoptotic Activity using Microplate Reading and Phase Contrast Imaging
- Live Cell Imaging of Apoptosis and Necrosis
- Automated, Multi-Parameter, Kinetic Methods to Quantify Cell Death
- Kinetic Proliferation Assay Using Label-Free Cell Counting
- Image-Based, Label-Free Methods to Detect and Quantify General and Directed T Cell Activation
- Monitoring Saccharomyces cerevisiea Growth with Brightfield Microscopy in Real Time
- Automated Hemocytometer-Based Live/Dead Cell Counting using Phase Contrast and Color Brightfield Imaging
- Use of Phase Contrast Imaging to Track Morphological Cellular Changes due to Apoptotic Activity
Infographic: How to Calculate Cell Count/Volume Using Automated Label Free Image Analysis
Related Applications:
Visual Abstracts:
BioTek’s Visual Abstracts are brief animated presentations describing the Augmented Microscopy workflow of a specific application.
Related Webinars:
Related Products:
- Lionheart FX Automated Microscope
- Lionheart LX Automated Microscope
- BioSpa Live Cell Imaging System
- Cytation 5 Cell Imaging Multi-Mode Reader
- Cytation 1 Cell Imaging Multi-Mode Reader
Learn more about Label-Free Cell Counting applications - search our Application Notes and technical documentation in Resources.