Determining the Intended Use of Cell Counting Results
Since the selection of cell counting methods should be fit-for-purpose, the first step is to understand or clarify the intended purpose of the measurements. While this may seem obvious at face value, it is important to think about the application of the cell counting method and what is ultimately to be gained. For example, a research lab may aim to document and publish novel biological processes or effects, and thus may seek to accumulate knowledge and incorporate best practices about the cell counting measurement quality early on and as a group. Meanwhile, cell therapy manufacturers may need to focus on meeting FDA requirements while being able to transfer assays from discovery to development, clinical trial sites, and manufacturing, ideally leveraging all assay improvements throughout the company. Both of these scenarios may also include multiple labs in multiple locations performing the same bioassays. Each of these goals require different considerations when it comes to choosing a method of cell counting.
Another critical component to determining intended use is what readout will be measured by the assay. This can be as simple as live or dead cell counts, but can also include measurements such as cell concentrations (alive or dead), percent viability, and biomarker or protein expression. These various metrics require different optimized conditions, especially when considered in the context of the sample type. The enormous range of biological sources for cell counting samples cannot be understated. From cultured or purified cell lines, whole tissues, isolated or cryopreserved blood samples, single-cell suspensions, to name a few, there are a plethora of considerations to choosing a cell counting method for each of these sample types. If manufacturing is the final goal, choosing the cell counting method will be dependent on the final product. For example, human bone marrow stromal cells for regenerative therapies have very different needs compared to tumor-infiltrating lymphocytes (TIL-T cells). Therefore, careful consideration of the intended use of the cell counting method must be employed to ensure the most robust and reliable results.
Researchers may download the Cell Counting Needs Assessment Worksheet or fill the worksheet on the website for determining the intended use of the cell counting results. Please contact Nexcelom if you would like to have one of our field application scientists review the assessment worksheet and provide guidance on selecting the best cell counting method for your needs.