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Calcium-flux assay on the FLIPR Tetra® HT Cellular Screening System

Calcium ions play a critical role in the electrophysiology of the heart and regulate the activities of motor proteins necessary for cardiac contraction. Direct acute drug effects on both electrophysiology and contractility can be detected by monitoring Ca2+ transients, making it a valuable tool in drug discovery and safety pharmacology assessment. The FLIPR Tetra® High-Throughput Cellular Screening System (Molecular Devices) is capable of simultaneous fluid dispensing and signal detection. Upon treatment with a calcium fluorescent dye, real-time changes in fluorescent calcium transients can be measured in Pluricyte® Cardiomyocytes at a high-throughput (96- and 384-well plate formats).

User guide

Pluricyte® Cardiomyocytes are validated and optimized for use on the FLIPR Tetra® System

Pluricyte® Cardiomyocytes have been optimized for use in combination with the FLIPR Tetra® System. Combining these technologies enables the detection of potential cardiotoxic effects of compounds at a high-throughput (validated up to 384 wells), and provides you with a predictive cardiac safety profile of drug candidates necessary for decision making at early stages of preclinical drug development.

You can find a step-by-step description of the analysis of fluorescent dye-based calcium transients of hiPSC-derived cardiomyocytes using the FLIPR Tetra® System in our User Guide:

Application

Cardiac safety assessment in hiPSC-derived cardiomyocytes using the FLIPR Tetra® HT Cellular Screening System

Case studies were performed to assess the effects of a set of known cardioactive compounds on Pluricyte® Cardiomyocytes using the FLIPR Tetra® High-Throughput Cellular Screening System (Molecular Devices). Calcium transients were determined to analyze specific cardioactive compound response parameters, including peak frequency, peak amplitudes, and average peak width. Below an example is shown of the effect of different reference compounds in Pluricyte® Cardiomyocytes.

Effects of Reference Compounds on Calcium Transients in Pluricyte® Cardiomyocytes

The negative control, 0.25% DMSO, shows a representative calcium transient pattern of untreated Pluricyte® Cardiomyocytes. Treatment of Pluricyte® Cardiomyocytes with cardioactive compounds, known to directly or indirectly affect calcium transients, demonstrated compound-specific effects:
The hERG channel blocker, E4031, at a concentration of 312 nM resulted in arrhythmic-like events. The calcium channel agonist, Bay K8644, at a concentration of 1.26 µM caused increased peak amplitudes, increased peak widths, and reduced peak frequency. By blocking L-type calcium channels with 19 nM nifedipine, Pluricyte® Cardiomyocytes show reduced fluorescent calcium transient peak amplitudes. Treatment with the β- adrenergic receptor agonist, isoprenaline (500 nM), induced increased peak frequency, and decreased peak width.

 

You can find the complete study in our application note: