Cell counters are tools for counting live and dead cells in a culture. Automated cell counters are an alternative to manual hemocytometer-based cell counting that offer more reliable and faster results. The hemocytometer, or counting chamber, was designed in 1874 by Louis Charles Malassez as the first instrument designed for cell counting. It consists of a thick glass microscope slide with a rectangular indentation that creates a gridded chamber where a sample is placed. Through a manual method of observation and counting, the number of cells in a sample is determined. Among the different reasons counting cells can be important are: ensuring you have enough cells to perform an experiment, identifying cell numbers that can affect the staining to perform an assay, measuring the magnitude of effects, and determining cell-loss for optimization of protocols.

There are two types of automated cell counters: image-based and electrical impedance–based systems (Coulter Counters). The former utilize brightfield or fluorescent microscopes coupled with CCD cameras to photograph the cells on the hemocytometer, and software to distinguish between and count live and dead cells. Similar to manual counting, many of these instruments use the trypan- or methylene-blue exclusion method to identify live cells.

On the contrary, electrical impedance–based systems cannot distinguish between live and dead cells (except by size), but only the number of cells present in the sample. These systems can also provide information regarding cell concentration and average cell size. In principle, as a cell passes through an orifice separating two chambers filled with an electrolyte solution, there is a change in electrical resistance. This resistance change is proportional to the size of a cell. In this system, concentration of cells can be a problem, as the orifice can get clogged.

Beckman Coulter (Danaher) and Thermo Fisher Scientific combine to account for half of the cell counter market. Beckman Coulter’s Vi-Cell product is based on the widely used trypan blue dye–exclusion method and features flow-through cell technology. Furthermore, Beckman Coulter’s z-series Coulter counters are among the most widely used electrical impedance–based technologies. Thermo Fisher commercialize only image-based systems. In 2014, the company launched Countess II, which became a popular device in public and private research labs. The company is the leader in aftermarket supplies, such as slides and dyes.

In 2016, the market for cell counters totaled $112 million and is expected to grow at a rate of more than 5% in 2017. Automated cell counters are time saving instruments that are gradually replacing traditional counting techniques with great success, which will be reflected in this year’s growth rate.

Cell Counters at a Glance:

Leading vendors:

• Beckman Coulter (Danaher)
• Life Technologies (Thermo Fisher Scientific)
• MilliporeSigma

Largest markets:

• Academia
• Hospital and Clinical
• Biotechnology

Instrument cost:

• $2,000–$55,000