Cell counting assays are commonly used in high-throughput microscopy screening enabling the precise determination of cell numbers within a sample. This method involves the use of fluorescent dyes that selectively label the cell nuclei or other cellular components, allowing them to be easily visualized and counted under a microscope.
The basic steps of a typical cell counting assay include:
- Sample Preparation: Cells are cultivated in suitable media and subjected to specific compounds or conditions, tailored to the experiment’s requirements.
- Cell Labeling: The introduction of fluorescent dyes or stains that target cellular components like DNA, RNA, or proteins is a critical step. Common choices include DNA intercalating dyes such as Hoechst, DAPI, or SYTOX, which stain cell nuclei.
- Imaging and Analysis: High-throughput microscopy captures images of the labeled cells. Specialized software then automatically segments and counts the cells within each sample.
Cell counting assays find applications across various domains, including drug discovery and cytotoxicity testing. They are particularly useful in high-throughput screening, where large numbers of samples need to be analyzed quickly and efficiently. In addition to conventional cell culture experiments, we offer co-culture assays. These assays recreate a more physiologically relevant microenvironment for drug testing. Notable examples include assessing the impact of immune cells on cancer cell growth and exploring the influence of microenvironments generated by specific cell types (e.g., fibroblasts on cancer cells).
Assay summary
| Monoculture | Co-culture | |
| Working principle | Microscopy counting of live or fixed cells involves visualizing, segmentation and automated counting of cells in a prepared sample. This method provides an estimate of the total cell count based on a representative area of the sample. | Microscopy cell counting of live or fixed cells involves visualizing, segmenting, and automating the counting of cells in a prepared sample. This method incorporates differential staining techniques to distinguish various cell types or subpopulations within co-cultures. It provides estimates of the total cell count and the counts of specific subpopulations, based on a representative area of the sample. |
| What is detected | Images of cells or nuclei | Images of cells or nuclei |
| Signal type | Fluorescence/Brightfield | Fluorescence |
| Platform | Automated fluorescence microscope | Automated fluorescence microscope |
| Sensitivity | 4/4 | 4/4 |
| Throughput | High | High |
| End-point/real time | End-point / Real-time | End-point / Real-time |
| Multiplexing | Yes, for example with Live/Dead or Apoptosis staining kits | Yes, for example with Live/Dead or Apoptosis staining kits |
| Model system | Adherent 2D cell cultures or cytospun suspension cells | Adherent 2D cell cultures or cytospun suspension cells |
Example output
