Weighing The Risk:
The Impact of Inaccuracy in Cell Counting

How many times in your life as a researcher do you count cells? Hundreds? Thousands? 1,2,3,4,5……120,121,122,123… Click, click, click…probably too often, potentially multiple times every day. The go-to method for many is still using trypan blue and the hemocytometer, eyes looking through a microscope, and your finger pressing the counter for every single viable cell. Automated cell counting instruments are vital in helping to count consistently but from clean, homogenous samples. However, within all scientific research, accurate and consistent cell counting remains a fundamental challenge when facing complex, clumpy, debris-ridden samples.

This pivotal process spans various sectors, from basic research to developing advanced therapies. Consistent cell concentrations are decisive for experimental accuracy and reproducibility. They are vital for assessing cell health and proliferation rates, optimizing culture conditions, and standardizing any experiment to gain deeper and more relevant insights.

All research using cell-based assays must be normalized to the cell number to allow data concordance. Cell counting accuracy is crucial for data comparability, determining cell potency of potential therapies, and quantifying viable effector cells. Precise cell counts are essential for developing next-generation chimeric antigen receptor (CAR) immune cells. 

One central dilemma revolves around the reliability of counts in diverse and low-viability samples, which are frequently marred by the presence of dead cells and biological debris. Research labs encounter various cell types, each with unique properties at different cell cycle stages, a range of debris and artifacts, and coming from a variety of sourcing, cryo-preservation, and processing methods, further complicating the cell counting process. How can you ensure the accuracy of cell counts when faced with complex samples that yield inconsistent and potentially misleading data? The importance of accurate cell counting cannot be overstated. In order to yield data that is comparable and meaningful, every sample must be normalized based on cell number. However, this normalization is fraught with obstacles if the starting materials are of low quality, clouding the interpretation and reproducibility of results. The diversity of these samples amplifies the complexity of identifying universally applicable cell counting methods.

Reliable systems are needed for standardization and quality control, ensuring that every assay, regardless of its complexity or the nature of the cells involved, adheres to a benchmark of consistency, reliability, and robustness. Pursuing such standardization is not just a matter of academic rigor but a practical necessity, given the high throughput and automated nature of many of these assays. 

By enriching cells for the highest viability and removing debris that is elusive to cell counters, assays can start with a truly consistent baseline.  The key is creating clean samples so cells can be counted accurately and consistently for input into the next step. By starting these sensitive analytical assays with clean samples, any erroneous signals propagated by debris, dead or dying cells can be avoided outright.

Manufacturers of sensitive research instrumentation often recommend a minimum of 70-90% viability of starting material to achieve unbiased outputs in applications like single-cell sequencing and functional metabolic or proteomic phenotyping. These considerations must be dealt with head-on.

Minimum viability is more than just a guideline; it is a cornerstone of quality assurance. Levitation Technology™ can now be used to enhance sample quality by separating viable cells from dead cells and debris without the requirement of cell labeling. The LeviCell® systems are poised to help boost research in this field by offering cleaner input samples for downstream applications, including more robust, high-quality cell count measurements that can underpin critical decisions in cell biology research and development. This novel platform provides an easy-to-use, scalable, more efficient, and gentle approach that ensures the maintenance of native cell states for diverse downstream applications.