Millicell^® ERS 3.0 Digital Voltohmmeter FAQs

The Millicell^® ERS 3.0 Digital Voltohmmeter combines an intuitive touchscreen interface for ease-of-use, standing in-well probe for more stable measurements, and convenient data analysis tools to streamline transepithelial electrical resistance (TEER) experiments. We’ve compiled a list of frequently asked questions relevant to instrument operation, maintenance, and more. Please refer to our User Guide for more in-depth answers on troubleshooting and protocol workflows.

I lost the website for the cloud. Where do I find it?

The web address for the Millicell^® Cloud application is https://app.millicellcloud.com. This is home to data from Millicell^® instruments such as the Digital Cell Imager (DCI) and Electrical Resistance System (ERS).

How do I setup my Millicell^® Cloud account?

The Millicell^® Cloud is intuitive and easy to setup. Start by going to https://app.millicellcloud.com and select “Sign up for an account”. Follow the on-screen directions and enter your organization’s information. All new Millicell^® ERS 3.0 units come with a cloud Free Trial Code on a sticker adhered to the instrument screen. Alternatively, you can purchase a cloud subscription. Enter your code and create your account.

How do I troubleshoot network connectivity problems on my Millicell^® ERS 3.0 instrument?

Hardware Checks

1. If you are trying to connect to a wireless network, make sure the EDIMAX wireless internet dongle is inserted into a USB port and that the dongle displays a blue LED light.
2. If EDIMAX wireless internet dongle is plugged in and the blue LED light is not lit, then there is potentially no power to the USB device, and you should try unplugging and plugging it in again to the same (and different USB ports).
3. If the EDIMAX wireless internet dongle is not fully inserted in the USB port, it will not be able to function.
4. If you are attempting to connect to a network by ethernet cable, make sure that the outlet you are using is turned on for ethernet access.
5. If you are attempting to connect to a network by ethernet cable, the instrument will display an ethernet symbol in the top right of the screen to confirm it is connected.

Software Checks

1. On the instrument, in Settings there is an option for Wireless Settings. Here you will find Connection Status, View Networks (for connecting to wireless networks), and Import Config.
2. Connection Status will tell you what the current connection status is for your instrument as well as what the MAC/IP address is for the instrument.
3. View Networks contains a list of networks visible to the instrument for wireless connection. If your network isn’t showing, back out of settings and re-enter the page to refresh or cycle power on the instrument to refresh.
4. Import Config gives users the option to insert a USB containing a network configuration file and import it to our device. This option can be utilized by your local IT department to help you get connected.
5. If you are connected to a network with timeout errors, try turning the instrument off and on again to refresh.
6. If the instrument shows that it is connected but you are still experiencing timeout errors, try moving closer to the internet source for a stronger signal.
7. If the instrument shows that it is connected but you cannot access the Millicell^® Cloud, check with your local IT department for institutional policy restrictions. This is unique to each organization and will require IT assistance. We suggest safe listing (or whitelisting) the Millicell^® ERS 3.0 MAC address with your local IT department. Whitelisting our instrument will permit network functions. 

How do I export my data from the ERS 3.0 instrument?

There are three modes on the instrument for data collection. Each provides a unique way to store and save your data.

1. In Quick Capture mode, the instrument will prompt the user to save data to a USB after taking measurements. The “Export to USB” button is available on the screen after pressing “Finish” on the measurement screen. From there, you will be prompted to insert a USB drive. Importantly, Quick Capture mode does NOT save data to the instrument and any data that is not exported will be lost.
2. In Work Offline mode, the instrument will save all measured data to the Experiment Plate used during the measurement. Press on a plate to bring up options for that experimental plate’s data. There is an option to export all data associated with a plate to a USB drive.
3. In a Cloud User Account, the instrument does not save data locally on-device. Assuming your instrument has stable internet connection, your data will be sent from the Millicell^® ERS 3.0 to the Millicell^® Cloud located at https://app.millicellcloud.com. Once you log in to your organization’s cloud account you will see all data from your Millicell^® instruments. Find the experimental plate map associated with your data and click on it. There is an option to download all raw data associated with this experimental plate to .csv at the bottom of the plate’s summary page.

How do I know my probe is working correctly?

In the Millicell^® ERS 3.0 User Guide, we have a detailed protocol for probe verification using potassium chloride (KCl) solutions. The User Guide is found on the product page for MERS03000. 

How do I adjust the probe depth for my specific insert?

Our new Millicell^® ERS 3.0 Standard Electrode Probes have an adjustable ring at the base of the probe body. This ring will sit on top of your cell culture insert and plate to stabilize your reading while simultaneously setting a uniform depth to your electrode measurements. Simply twist the adjustable ring to raise or lower the probe into the desired position. The shorter probe leg is the apical (in insert) electrode, which should be a few millimeters above your cell culture. Make sure the entire gold electrode is submerged in media for optimal accuracy and measurement consistency.

How do I clean my probe?

The User Guide goes into further detail about this process. The User Guide is found on the product page for the MERS03000.

Cleaning Between Wells

We recommend rinsing the probe in the same media you are using for measurements. This will keep the ions balanced on the electrode surface. If you are using a biological contaminant (bacteria or virus) that needs to be removed, you can clean the electrodes in alcohol, bleach, or 3% hydrogen peroxide, but we strongly advise resting the probe in PBS for ion balancing and chemical removal before returning to cell cultures.

Cleaning Between Plates

We recommend cleaning electrodes in 70% ethanol between plates, allowing the electrodes to air dry, and rinsing off alcohol residue in PBS. If you need to use a stronger cleaner, please refer to the list below.

Electrode Chemical Compatibility

Chemical	Recommended Exposure for Cleaning
Ethanol/Isopropanol Alcohol, 70%	15 minutes
Ethanol Wipe	1 minute
Enzyme Detergent, 1% (Tergazyme® or Alconox®)	30-60 minutes
Hydrogen Peroxide, 3%	30 minutes
Sodium Hypochlorite (Bleach), stock ~ 5% sodium hypochlorite	15 minutes
Sodium Hypochlorite (Bleach), 10% stock ~ 0.5% sodium hypochlorite	15 minutes

Caution: Repeated rubbing or scratching will damage the coating of the electrode, which can severely damage the integrity and accuracy of measurements.

Note that we also tested and confirmed probe electrode compatibility with KCl, PBS, and cell culture medium with FBS.

Which inserts are compatible with the Millicell^® ERS 3.0?

The following inserts were tested as part of validation of the instrument and electrode probe.

Well Size	Brand
6-well	Millicell® 6-well hanging inserts
	Millicell® 30 mm standing inserts
	Corning® Transwell® 6-well hanging insert
	cellQART® 6-well hanging insert
	Falcon® 6-well hanging insert (CLS353502)
	Nunc® 6-well standing insert (TMO140644)
12-well	Millicell® 12-well hanging inserts
	cellQART® 12-well hanging insert
	Falcon® 12-well hanging insert
	Corning® Transwell® 12-well hanging insert
	Nunc® 12-well standing insert (TMO140652)
24-well	Millicell® 24-well hanging inserts
	Millicell® 12 mm standing inserts
	Corning® Transwell® 24-well hanging insert (CLS3397)
	cellQART® 24-well hanging insert
	Falcon® 24-well hanging insert (CLS353504)
	Millicell® 24-well Cell Culture Insert Plate PET (PSST010R)
	Corning® Costar® HTS Transwell 24-well plates
	Thermo Scientific Nunc® standing insert 24-well plate

How do I store the instrument and probe when not in use?

Sanitize the electrodes with 70% ethanol and immediately rinse with Milli-Q^® or distilled water. Do not allow the electrode to dry without first rinsing to remove salts and proteins. After proper cleaning, store electrodes protected from light. Sunlight and UV light from cell culture hoods may damage the electrode and probe. Store probes in the plastic container in which they were received to prevent scratching and other physical damage.

How long does the battery last?

For the Millicell^® ERS 3.0, the battery will last four hours of continuous use from full charge. According to the battery manufacturer specifications, the battery will charge to 80% of initial capacity after 800 cycles.

Can I use my instrument while it is charging?

The instrument can be used while charging the battery. This will not impact your measurement readings.

Does the instrument work without the battery?

The instrument fully functions without a battery on wall outlet power, but voltage mode is most stable on battery power only.

How do I format a USB drive for the Millicell^® ERS 3.0?

Insert the USB drive into your computer. Right click on the USB drive and select “Format”. For Millicell^® ERS 3.0 compatibility, select “FAT32” format. Please be aware that formatting a USB drive will permanently delete all its contents, so make sure to back up your personal files before doing this.

Why does Voltage mode appear to drift instead of steadily remaining on one value?

Ions on the surface of your electrode drastically impact your measurement stability. To equalize the ions on the surface of your electrodes, place the probe in PBS for at least 30 minutes. This will improve the reading stability and decrease drift. Always make sure to use the buffer wells to background subtract your offset in this mode. The temperature sensor is active at the beginning of a well reading. This potentially impacts the first readings of your voltage measurement because the electrical current in the temperature sensor displaces ions on the electrode. This requires a moment for the sensor to restabilize, but the instrument will still read accurately.