Voltage Sensitive Dye Imaging of Membrane Potential

For More Detailed Analysis of Neuronal/Cardiac Activity

Brain Slice (Hippocampus)
Isolated Heart

Cultured Cardiomyocytes
Isolated Heart (Ventricular Fibrillation)

Table of Contents

Higher throughput in comparison to electrophysiological methods
3 Advantages of Voltage Sensitive Dye Imaging
Sample data
About Us
High-Speed Imaging Systems specialized for Voltage Sensitive Dye Imaging
Download - Brochure
FAQ
Free Download - Data Analysis Software

Higher throughput in comparison to electrophysiological methods

Electrodes are generally used to record electrical activity of biological samples. However, methods using electrodes have the following disadvantages.

Activity can only be recorded near or around an electrode insertion site
Physical damage to sample can be caused by electrodes
Specialized skills and Experience are required for electrode insertion
Only electrical activity can be recorded

Voltage sensitive dye imaging can solve these problems.

What is Voltage Sensitive Dye (VSD)?

Voltage sensitive dye changes its absorbance and fluorescence intensity when membrane potential changes in a stained brain or heart tissue.

By using voltage sensitive dyes as chemical probes and capturing changes in light intensity with the use of a high-speed imaging device, it is possible to image in real time the activity of where, when, and how much excitation or inhibition occurred, in the brain and heart.

The main advantage of optical mapping with voltage sensitive dye is that spatial information can be obtained without reducing the number of recording points, simply by changing the magnification of the optics.

(A) Glass electrode penetrating the neuronal membrane.
(B and C) Metal electrodes for recording extracellular activity
(D) Voltage sensitive dyes are molecular probes that enter the neuronal membrane and convert membrane potential into fluorescence intensity. The figure shown in E is the action potential of a giant squid nerve axon; the solid black line is the intracellualr recording and the red dots show the voltage sensitive dye recording.

3 Advantages of Voltage Sensitive Dye Imaging

1. Non-invasive recording of active in entire tissue or sample

No physical damage due to the use of light to capture changes in action potentials of brain/heart tissue.
Activity and signal propagation can be visualized simultaneously in a wide field of view

2. Easy recording without electrophysiological skills

Experience of electrophysiological techniques such as patch-clamp and intracellular recording is not required.

In addition, more data can be acquired, compared to conventional techniques using electrodes.
Signals can be recorded at 10,000-65,536 points.

3. Multi-parametric recording of Vm, Ca²⁺, metabolism...etc is possible.

It is possible to simultaneously record changes in calcium concentration and/or metabolism-related indicators, as well as membrane potential, when suitable fluorescence dyes/filters are chosen.
Simultaneous imaging of membrane potential and calcium transient activity in isolated human heart

Sample data

Examples of animals, samples, and probes/methods used for optical mapping

Animal	Sample		Probe/Method
Pig Rat Mouse Zebrafish	Isolated heart	- Langendorff perfused heart - In Vivo heart	- Simultaneous dual wavelength imaging of membrane potntial and ca²⁺ transient - Panoramic imaging of heart by using multiple cameras
-	Cultured cardiomyocyte sheet	- iPSC-derived cardiomyocytes (iPSC-CMs)	- Voltage sensitive dye imaging - Calcium imaging
Monkey Rat Mouse	In Vivo brain	- Somatosensory cortex - Visual cortex - Auditory cortex	- Voltage sensitive dye imaging - Imaging with FRET, GCaMP, GEVI - Intrinsic optical signal imaging based on hemoglobin and flavoprotein autofluorescence
Rat Mouse	Brain slice	- Hippocampus - Somatosensory cortex - Visual cortex - Auditory cortex	- Voltage sensitive dye imaging - Intrinsic optical signal imaging

High speed voltage sensitive dye imaging of spontaneous activities in cultured neuronal network

Monolayer of neonatal mouse ventricular myocyte stained with voltage sensitive dye

Voltage sensitive dye imaging of isolated langendorff pig heart at 1,818fps

Voltage sensitive dye imaging of brain slice using MiCAM05-N256

About Us

SciMedia specializes in complete turn-key, high speed optical mapping systems for neuroscience and cardiac research. Our cameras utilize unique CMOS sensors, which are designed to detect voltage, calcium, and intrinsic signals, while providing an optimal combination of high speed, high resolution, and high signal to noise ratios.

Since 1998, SciMedia has been supporting customers and collaborating with labs internationally. Based on ideas and requests from researchers, we strive to offer the highest quality optical mapping systems including both hardware devices and software..

Our Advantages

Custom CMOS image sensors having high speeds, wide dynamic range, and low noise

Our cameras are used to detect both voltage sensitive dye signals and calcium signals at optimal S/N ratios.

Imaging system, optics, and software developed based on 24 years of experience

Turnkey systems are ready for immediate use. Custom-made products are also available upon customers requests.

650 scientific research papers have been published using our imaging systems

Our systems are used by customers in over 220 universities, research institutes, and companies. 420 units have been installed in the last 24 years.

High-Speed Imaging Systems developed for Voltage Sensitive Dye Imaging

High Speed Imaging System
MiCAM03-N256

Standard model for high speed imaging with
excellent balance of high speed and high S/N ratios

- Resolution: 256x256 - 32x32 pixels
- Maximum frame rate: 1,923fps (at 256x256 pixels)
- Camera port: 2
Fluorescence Mesoscope
THT Mesoscope

Optical system for detecting low light fluorescence
in a wide field of view

- Low magnifications with high N.A values : suitable for mesoscopic fluorescence optical mapping
- Multifunctional: also can be used as a fluorescence beam splitter

Download - Brochure

High Speed Imaging System MiCAM Series (2019)
MiCAM05-N256 and MiCAM03-N256

FAQ

What is membrane voltage sensitive dye?: Membrane voltage sensitive dye changes its fluorescence intensity according to membrane potential.

What is optical mapping of membrane potential?: Optical mapping is based on traditional electrophysiology methods, but optical imaging is also utilized to further understand membrane potential in cell networks over both space and time. Membrane potential is recorded optically in two dimensions using voltage sensitive dye, and differs from patch recordings of membrane potential activity, which uses conventional electrodes. The optical mapping method allows researchers to image a large field of view with minimal invasiveness.

What kinds of biological samples can be used for optical mapping?: The optical mapping techniques have been used to image activity in in-vivo animals, in-vitro samples such as tissue slices, isolated muscle tissues and cultured cells, and other biological preparations.

What is required for optical mapping of membrane potential?: The MiCAM system includes a camera, processor, data acquisition software, data analysis software, software license, personal computer with interface, and PC/monitor. Additional equipment, such as a fluorescence microscope, bright and stable-light source, anti-vibration table, and isolator, etc…, are also necessary, depending on the type of experiments.

What is MiCAM?: MiCAM is the high speed camera series specifically designed to detect very small changes in light levels at high speeds, high resolution, and high signal to noise ratios. All of the cameras are designed and manufactured in Japan.

What is required for simultaneous acquisition of two wavelengths?: An additional camera head and fluorescence beam splitter are required.

Is it possible to test a demo system before the purchase?: Yes. Please feel free to contact us if you are interested in a demo.

Free Download - Data Analysis Software

Perform data analysis with actual voltage sensitive dye data. Data analysis software, BV_Ana, and isolated heart/brain slice data can be downloaded.

(Note: Sales and support for BV_Ana have ended. The latest version of data analysis software is BV Workbench.)

BV_Ana

BV_Ana is the data analysis software for MiCAM series imaging systems. It has an intuitive user interface and is designed for users to quickly analyze data after image acquisition. In addition to quick image and movie display with user selected wave display, various types of filters are available, as well as data export functions for multiple data formats including avi, jpeg, csv, simple binary/ascii, multi-tiff, etc…Creation of data files for presentations is very simple and straightforward.

Key Functions

Image display	dF display, real image display, image gain setting, threshold level setting, color bar display, color reversal, tile image display, etc.
Time control	Video playback, video speed control, frame by frame playback, adjustment of playback speed, Frame number/time display, etc.
Waveform display	Waveform display by double-clicking on image, expanding/reducing the displayed time range, spatial filters, temporal filters, etc.
Supported data format	- Data acquired from MiCAM ULTIMA, MiCMA02, MiCAM01 - 16bit gray-scale multi-tiff
Output files	AVI/BMP/TIFF/JPEG/CSV/ASCII/Binary

Recommended Specifications

OS	Windows 7 32bit/64bit Windows 10 64bit
RAM	256MB or more
Display resolution	1,920x1,200 pixels recommended

How to install/use BV_Ana

1. After registering your email address, click the link in the email that will automatically be sent to you, then download the zip file.
(See the bottom of this page for email registration instructions.)

Zip file including the installer of BV_Ana and sample data

2. Unzip the downloaded zip file.

3. Double-click the BV_Ana installer in the folder to start installing BV_Ana.

Installer of BV_Ana

4. After installation, click the icon of BV_Ana in the Start menu to start BV_Ana.

Icon of BV_Ana

5. BV_Ana is opened.

6. Select “Format=All”.
Expand the "Folder" tree to display the "data" folder, which is included in the downloaded folder. Double-click the data name displayed in the “File List” to open the data on the canvas.

7. Click the Control tab. Click the [auto] button below the [Mon] slide bar to automatically adjust the gain of the background image.

8. Double-click on the image to display a waveform.

9. Click and drag the point on the image, and the waveform display will change accordingly.

10. Click on the waveform display. Membrane potential (fluorescence) change at the selected point will be displayed in pseudo-color.

11. Click "Img" arrows or drag scroll bar to adjust displayed gain of pseudo color. Click "Wave" arrows or drag scroll bar to adjust gain of waveforms.

12. Click the "movie" button to play the video.

13. To smooth the image data and wave/s displayed, "Spatial filter" and/or "Cubic filter" on the "Calculation" are helpful.

14. By double-clicking on the image, multiple waveforms can be displayed.

15. By clicking and dragging a pointer, the waveform (light intensity change) at different locations can be displayed.