Xpress.4U LightPace
Cor.4U® Kit

The Xpress.4U LightPace Cor.4U® Kit contains LightPace mRNA, Cor.4U® Cardiomyocytes and Complete Culture Medium, and all proprietary reagents needed for optical pacing of Cor.4U® Cardiomyocytes, which have been manufactured under strict QC conditions. The Kit comes equipped with a fully optimized and validated protocol, including a specific pacing protocol, as well as a Quick Guide for the lab.


Product Information

Most cardioactive drugs affect the spontaneous beat rate of hiPSC-derived cardiomyocytes. Since the repolarization duration of hiPSC-derived cardiomyocytes is dependent on the beat rate, it is necessary to standardize the beat rate. This can be achieved by optical pacing using the Xpress.4U LightPace Cor.4U® Kit.

Product Data

Product Specifications


Catalog number(s)


Xpress.4U Technology

The Xpress.4U™ LightPace technology is based on fusion of the mRNA containing vesicles with the cell membrane thus avoiding early lysosomal degradation and induction of stress pathways



To guarantee optimal results, specific Cor.4U® Cardiomyocyte batches have been selected for use with Xpress.4U™ LightPace

Assay Window

Pacing of transfected Cor.4U® Cardiomyocytes can be performed 1-3 days after transfection, with an optimal pacing responsiveness 2 days after transfection

Complete Kit

1 Kit contains enough reagents to transfect 2 Lumos™ OptiClear 48 well plates. Contents: LightPace mRNA; Neutralization buffer; Liposomes; Dilution buffer; Cor.4U® Cardiomyocytes; Cor.4U® Complete Culture Medium

Recommended Storage

Xpress.4U™ LightPace Cor.4U® reagents: -80°C

Cor.4U® Complete Culture Medium: -20°C

Cryopreserved Cor.4U® Cardiomyocytes: liquid nitrogen vapor phase

Validated Application

Validated for use on Maestro and Lumos™ multiwell light delivery systems (Axion BioSystems)



An ultrasonic bath is required