Label-free cell analysis is a fast-growing technology segment in the life science instrumentation industry. There are a handful of label-free cell analysis systems on the market based on measuring the impedance changes of cells in a solution. In order to perform this type of label-free cell analysis, the cells of interest are either adhered to or suspended in wells. An AC current is then applied to the solution, and the impedance of the cells is measured. Changes in impedance can be caused by a variety of factors including an increase in cell density, cell mortality, interaction with surrounding cells, morphological changes, and changes in cell’s electrophysiological properties. Label-free cell analyzers are most often used to monitor cytotoxicity, proliferation, migration and electrophysiology.

The traditional method of measuring cell parameters requires a labeling step, which can harm the cell or alter its natural physiological state, leading to unreliable results. Impedance technology overcomes these limitations by allowing scientists to measure the same parameters by passing a small dose of electrical current through and around the cells. Although these systems have a relatively high initial system price, label-free cell analyzers have a lower operational cost as the need for fluorescent dyes or labels is nonexistent or the sample preparation is significantly reduced. This is very attractive to high-throughput users, who typically spend more time on sample preparation.

The vendors competing in this market include Molecular Devices, Applied BioPhysics and Roche Applied Sciences. Molecular Devices offers two label-free cell analyzers, the CellKey 96 and CellKey 384. The CellKey is capable of analyzing both adherent and non-adherent cell types. While the system is designed to measure G-protein coupled receptors (GPCRs), it can also perform measurements on a variety of ligand-gated channels and other cellular properties.

Applied BioPhysics’ electrical impedance instruments include the ECIS 8Z, ECIS Z and ECIS Ztheta. The ECIS 8Z and Z are designed to measure simple impedance parameters. The ECIS Ztheta, in addition to having 96-well format capability, can give more complex measurements including resistive and capacitive changes in impedance.

XCELLigence is Roche’s label-free cell analysis system, which was introduced in collaboration with ACEA Biosciences. The system comes in four configurations: xCELLigence SP, MP, DP and HT. The DP model is a low-throughput unit that can integrate up to three 16-well plates. The SP model is designed to perform impedance measurements on one 96-well plate, while the MP model can integrate up to six 96-well plates simultaneously. The xCELLigence HT model uses 384-well plates for real-time and label-free cell-based assays.

The biopharmaceutical industry will fuel market growth as the technology becomes more accepted.

Impedance-Based Label-Free Cell Analyzers at a Glance:

Leading Suppliers

• Roche/ACEA

• Molecular Devices (Danaher)

• Applied BioPhysics

Largest Markets

• Biopharmaceutical

• Academia

Instrument Cost

• $100,000–$250,000