Axion’s contribution to establishing microelectrode array (MEA) technology as an accessible, versatile research tool cannot be defined by a single advantage. It’s the cumulative effect of our commitment to growing our MEA platform to include instruments, accessories and software working in unison.
The evaluation of electrically-active cells has historically been tedious, requiring months of training to painstakingly study single cells in low throughputs. By culturing a network of cells over the high electrode count arrays available in each well of our MEA plates, Axion BioSystems’ MEA systems capture activity across an entire population of cells—with far greater data points per well—detecting activity patterns that would otherwise elude traditional assays.
When it matters, use Maestro MEA
Why did Maestro MEA users achieve the best data in the CiPA Phase II study? It's not by chance. Axion have designed the Maestro MEA platform to be the complete solution for MEA hiPSC-cardiomyocyte assays.
WHAT IS MEA?
Axion’s microelectrode array (MEA) plates have a grid of tightly spaced electrodes embedded in the culture surface of each well [A]. Electrically active cells, such as neurons or cardiomyocytes, can be cultured over the electrodes [B]. Over time, as the cultures become established, they form cohesive networks and present an electrophysiological profile. The resulting electrical activity—spontaneous or induced firing of neurons, or the uniform beat of cardiomyocytes—is captured from each electrode on a microsecond timescale providing both temporally and spatially precise data [C].
NEURAL NETWORK RECORDINGS
Electrical activity is captured from neurons (orange) cultured over electrodes (gray circle). The Maestro MEA system detects key parameters of neural network activity, including functionality, excitability, and connectivity.
The Maestro MEA system detects key parameters of cardiomyocyte activity, including depolarization, propagation of excitibitality, repolarization, beat timing and irregular beating (arrhythmia).
When analyzing cellular networks, mixed cell populations or variable activity may make complete characterization of the population difficult. Electrical stimulation using electrodes in the MEA well is one possible way to control cellular and network behavior. However, electrical stimulation is not targeted to specific cell types and can produce data artifacts.
Optogenetic stimulation is a light-based technique providing artifact-free, selective control over cultured cell networks. A simple viral transduction process introduces light-sensitive, membrane ion channels called opsins into specific cell types through genetic targeting. The opsin family contains a diverse group of ion channels that allow passage of charged ions through the membrane when stimulated at specific wavelengths. For example, Channelrhodopsin-2 (ChR2) is a non-specific cation channel that depolarizes electrically active cells causing action potentials to fire when irradiated with blue light. Other opsins, such as archaerhodopsin (Arch) or halorhodopsin (NpHR) are anion channels that respond to green or orange light, respectively, with membrane hyperpolarization, suppressing cell activity.
When used in conjunction with an MEA assay, opsins can be easily introduced into cultured cells on the MEA plate. A viral vector, prepackaged to contain the desired opsin (e.g. ChR2), the desired promoter (which targets the opsin to a selected cell type, e.g. a universal CAG promoter), and a fluorescent tag (to later visualize which cells are expressing the opsins, e.g. GFP) is added to cells in culture. Within a few days, cells express the opsin and are ready for experimentation. The MEA plate is placed in the Maestro where it records cellular activity from the bottom of the plate, while Lumos provides simultaneous optical stimulation and advanced cellular control from the top.
Axion BioSystems has revolutionized in vitro optogenetics with Lumos by providing optical stimulation with the highest commercially available throughput and flexibility. Available in 24-, and 48-well formats, with four individually-controlled LEDs per well spanning the spectrum of the most commonly used opsins. Each of the 96 (Lumos 24) or 192 LEDs (Lumos 48) have been tuned for optimal power providing a range of intensity for full illumination and activation per well. Complete integration into AxIS provides a user-friendly interface to generate flexible stimulation profiles.
Take control of specific neurons in a mixed population or unify beat rate of cardiomyocytes across the plate for accurate and predictive cardiac safety assays. Axion innovation makes it all possible with a single integrated platform.