EVOM™ Manual replaces EVOM3, EVOM2 and ERS-2.
EVOM™ Manual replaces all WPI-manufactured manual TEER meters, including EVOM3, EVOM2 and MilliCell® ERS-2, all of which have been discontinued.
This manual TEER measurement meter now has automatic data logging. EVOM™ Manual has a low noise design that offers greater resolution and accuracy in your TEER measurement protocol. It has automatic 20× sample averaging, which improves accuracy and stability. Choose from the adjustable fixed measurement currents (2, 4 or 10 μA). Resistance measurements auto range from 1 to 100000 Ω or with three fixed current ranges. The reliable low current, low voltage design prevents metal ion transport, and it has fast resistance stabilization on low levels under 200 Ω with resolution to 0.1 Ω. Use the ergonomic tilt stand for low glare operations. You get automatic plate indexing operation with or without control well subtraction for resistance and potential difference (PD) measurements, and continuous data logging via USB (PC, Mac, Linux).
Tissue sampling frequency: 12.5 Hz
Sample averaging: 20 samples/s.
Resistance ranges: 0 to 10000 Ω, 0 to 50000 Ω, 0 to 100000 Ω
Auto mode: 1 to 100000 Ω auto current 2, 4, 10 μA
Resistance resolution: 0.1 Ω (under 200 Ω); 1 Ω (over 200 Ω)
Resistance accuracy: 0.1 Ω (under 200 Ω), 1 Ω (over 200 Ω) 0.1%; 100,000 Ω ±2 μA (to 105 KΩ)
Voltage resolution: 0.001 V, 0.1 mV
Accuracy resistance: 0.1 Ω (200 Ω); 1 Ω (above 200 Ω)
Accuracy voltage: ±0.1 mV
Display update rate: 0.5 s
Charging period: 5.5 h (power off); 6 h (run time)
Charge current: 200 mA
Power consumption: ~250 mA
Certifications: CE marked.
Accessories information: Optional STX4 electrode set for EVOM™ MANUAL with removable blades (STX4 electrode newest chopstick electrode) – Electrode blades are replaceable. The electrode tip (active sensing area) of STX4 is shorter than the STX2-PLUS. The STX4 electrode fits ideally on 24-well hanging transwells cell culture inserts (e.g., Corning 3470) and can stay hung on top of these. The STX4 electrode has improved measurement precision since the electrode design, which is similar to the STX2-PLUS, eliminates or minimizes variabilities introduced by the electrode positioning seen with the STX2 or STX3. The STX2 or STX3 electrode is handheld. No chloriding necessary – Electrode tips are specially coated, requiring no chloriding (maintenance step) to ensure proper electrode functionality when measuring TEER of cellular layers like epithelial cultures. Chloriding was necessary for the STX2-PLUS. Less liquid volume needed – This electrode requires with less liquid volumes than required for STX2-PLUS electrode to keep the tips immersed and able to provide stable readouts. Shielded from radio frequency interference (RFI) – This STX4 electrode has a shielded cable and eliminates or minimizes any interference (from electrical sources or cell phones) affecting the TEER measurement read outs. The STX4 electrode is the most recent version of chopstick electrode for the EVOM™ Manual (or the older version, EVOM3), and it is designed to facilitate measurements of voltage (potential difference: PD) and resistance (transepithelial electrical resistance: TEER) of cultured epithelia (cellular layer) grown onto permeable membrane inserts in 12- and 24-well tissue culture plates. STX4 can measure directly inside the well plates with 12 and 24 inserts. The STX4 is designed primarily for 24-well hanging inserts or transwells (e.g., Corning 3470), and the electrode’s best performance can be seen in this format.
Optional EVOM™ Manual Endohm Electrode for TEER - Endohm provides TEER measurement in culture cups. The new EndOhm chamber upper mount is made of polycarbonate and unaffected by alcohol. The glass chamber is easier to clean and more scratch resistant than the prior versions. The EndOhm is not recommended for incubator use due to risk of the glass cracking. Adjustable apical electrode height. Crystal clear glass chamber allows visualization of apical electrode positioning. New insert holder with 120° tri-supports for three leg inserts Three sizes cover a range of well cup sizes from a variety of manufacturers. Compatible with EVOM3 and EVOM™ Manual. Stability and reproducibility superior to the STX4 electrodes to 1% tolerance. EndOhm chambers compatible with EVOM™, EVOM2, and Millicell® ERS and ERS2. Using WPI’s EVOM™ Manual resistance meter, Endohm chambers provide reproducible resistance measurements of endothelial and epithelial monolayers in culture cups. Transfer cups from their culture wells to the Endohm chamber for measurement rather than using hand-held electrodes. The chamber and the cap each contain a pair of concentric electrodes: a voltage-sensing silver/silver chloride pellet in the center plus an annular current electrode. The height of the top electrode can be adjusted to fit cell culture cups of different manufacture.
Optional STX HTS EVOM™ manual electrode - STX electrode for HTS cell culture plates. Designed for use with 24-well HTS plate (Corning Costar and Corning Falcon) and with 96-well plates (Millipore). Improved accuracy down to 5 Ω. Sterilized with EtO, alcohol or bactericide. Electrode design reduces chance of contamination. Semi-permeable HTS (high throughput screening) culture plates have become a standard tool for pharmaceutical and institutional research in epithelial transport. HTS culture plates have well cups which are bonded together into a single assembly and are not removable. This makes the plates ideal for automated applications, but imposes a significant inconvenience when TEER must be measured in the absence of an automated system. WPI’s STX HTS series of EVOM™ electrodes, replacing the STX100 electrodes, provide a cost-effective alternative to automation, allowing HTS well plates to be measured manually using a hand-held electrode.
Ordering information: Electrode (sold separately) is required for use with EVOM™ Manual; please choose one.
Caution: The EndOhm is not recommended for incubator use due to risk of the glass cracking.
