Voltage-Sensitive Dyes for Cardiac Research

Voltage-sensitive dyes are currently used for cardiac research from single-cell to whole-heart applications (Video provided by Peter Lee, Essel R&D). Similar to neuro applications, sensitivity, staining, brightness, and response dynamics are among the chief considerations in choosing the best dye for a given application. Potentiometric Probes produces several dyes that have been used successfully for diverse cardiac applications. Our dyes have diverse spectral properties including far red-shifted dyes and Potentiometric Probes can help you select the best dye for your cell, tissue, or whole-organ assay and preferred imaging modality.

In this video, spontaneously beating human stem cell-derived cardiomyocytes stained with ElectroFluor630TM (aka Di-4-ANEQ(F)PTEA) allows ratiometric optical action potential recordings.

The ratio of two excitation wavelengths boosts signals and removes artifacts due to non-uniform staining, bleaching, and the motion of these beating (contracting) human heart cells in a dish.

The Igor Efimov lab at George Washington University studies cardiac arrhythmia disorders and treatments.

Ventricular fibrillation and tachycardia can even be studied in human hearts (link to citation) with voltage-sensitive dyes such as Di-4-ANBDQBS (6).

Optical electrophysiology in vivo pig model. Ratio imaging solves the motion problem during beats.

Our new fluorinated long wavelength VSD facilitates loading and has low toxicity.

Large animal models are a key step toward human imaging.

Key Products and Applications

  • Di-4-ANEPPS and Di-8-ANEPPS are classic voltage-sensitive dyes with rapid response kinetics that have been used for cardiac recordings for decades (2, 5). Although limited by sensitivity, dyes of this kind can provide excellent signal-to-noise based on brightness and photostability. Additionally, ratiometric techniques (1, 3, 5) may be employed for artifact removal such as slow bleaching or rapid movement artifacts.

  • More recently, fluorinated dyes such as ElectroFluor530™ (aka Di-4-AN(F)EPPTEA)  and ElectroFluor550™ (aka Di-4-AN(F)EP(F)PTEA)  were developed for improved signal-to-noise and these patented dyes promise to take over from the classic dyes as the new workhorses of voltage imaging.

  • Long wavelength dyes such as CytoVolt 1 (Di-4-ANBDQBS) and CytoVolt 2 Di-4-ANBDQPQ (4) were developed for improved sensitivity and spectral compatibility with blood-infused, whole-heart preparations. Impressive research using this patented technology shows the electrical activity of the heart in a striking, highly detailed, real-time view. These experiments point to potential future clinical applications of voltage-imaging in the heart. Potentiometric Probes is working with Cytocybernetics to supply these dyes, develop novel assays for their use, and work on further improvements.

    1. Herron, T. J., P. Lee, and J. Jalife. 2012. Optical imaging of voltage and calcium in cardiac cells & tissues. Circ Res. Pubmed

    2. Loew, L. M., L. B. Cohen, J. Dix, E. N. Fluhler, V. Montana, G. Salama, and J. Y. Wu. 1992. A naphthyl analog of the aminostyryl pyridinium class of potentiometric membrane dyes shows consistent sensitivity in a variety of tissue, cell, and model membrane preparations. J Membr Biol. Pubmed

    3. Lee, P., C. Bollensdorff, T. A. Quinn, J. P. Wuskell, L. M. Loew, and P. Kohl. 2011. Single-sensor system for spatially resolved, continuous, and multiparametric optical mapping of cardiac tissue. Heart Rhythm. Pubmed

    4. Matiukas, A., B. G. Mitrea, M. Qin, A. M. Pertsov, A. G. Shvedko, M. D. Warren, A. V. Zaitsev, J. P. Wuskell, M. D. Wei, J. Watras, and L. M. Loew. 2007. Near-infrared voltage-sensitive fluorescent dyes optimized for optical mapping in blood-perfused myocardium. Heart Rhythm. Pubmed

    5. Montana, V., D. L. Farkas, and L. M. Loew. 1989. Dual-wavelength ratiometric fluorescence measurements of membrane potential. Biochemistry. Pubmed

    6. Aras, K. K., N. R. Faye, B. Cathey, and I. R. Efimov. 2018. Critical Volume of Human Myocardium Necessary to Maintain Ventricular Fibrillation. Circ Arrhythm Electrophysiol. PubMed