Chinese Hamster Ovary (CHO) cells are an epithelial-like cell line commonly used in biological and medical research. Developed over 50 years ago, they have been used in innumerable studies ranging from genetics to cytotoxicity. They are highly amenable to transfection and have become the most popular cell line for manufacturing recombinant proteins, including therapeutics.
To count CHO cells without staining, I use the predefined setting ‘Cells A’ in SoftMax Pro Software. This works really well on CHO cells that are anywhere from 5% to 95% confluent. We’ve been able to get excellent correlation between Stain-Free counts and fluorescent nuclear counts from the very same samples. (See Fig. 2 & 3).
Getting more accurate StainFree counts. When imaging in the TL channel, instead of using a Focus Adjustment height that gives you the sharpest image possible, try lowering your Focus Adjustment to a somewhat more negative position, e.g. from 0 to -20. You want the cells in your image to have bright centers and dark edges. This will save you lots of time and give you better results with the predefined analysis settings.
CHO Cells Analysis Toolkit
- SpectraMax® i3 Multi-Mode Microplate Detection Platform
- SpectraMax® MiniMax™ 300 Imaging Cytometer
- SoftMax® Pro Software
|Optical configuration||SpectraMax MiniMax 300 Imaging Cytometer|
|Wavelength settings||Transmitted light|
|Image acquisition settings||Exposure: 7 ms|
|Image analysis settings||Analysis type: Discrete Object Analysis Wavelength for finding objects: TL|
|Find objects||Setting: CellsA|
|The ‘CellsA’ predefined image analysis setting enables a simple one-click analysis of CHO cell counts. Image acquisition and analysis settings may vary depending on assay conditions, microplate used, and other factors.|
About StainFree Cell Detection Technology
Imaging cell-based assays typically requires the use of fluorescent probes that can be toxic to living cells or may only function in fixed cells. A label-free method for analyzing cell counts and cell confluence enables researchers to quantitatively monitor cell proliferation and health without time-consuming workflows that may disrupt cell viability.
The SpectraMax i3 Multi-Mode Microplate Platform with MiniMax 300 Imaging Cytometer uses unique, patent-pending StainFree Cell Detection Technology that allows you to perform cell proliferation, cytotoxicity, and other assays without nuclear stains like DAPI, which intercalates with DNA, or live cell dyes that are actually toxic to cells in the long term.