As WPI’s EVOM™ line of TEER/TER (Transepithelial Electrical Resistance) measurement meters continues to evolve, we have seen similar advancements in the design of its electrodes. The new STX4 electrode (EVM-EL-03-03-01) (LINK) offers many advantages over the STX2-PLUS released in 2020. Both the STX4 and the STX2-PLUS are improvements on the STX2 and STX3 designs used with the EVOM, EVOMX, MilliCell® ERS and ERS2, and EVOM2. In this article we will compare the two newest designs.


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The advanced design of both the STX4 and the STX2-PLUS offer greater measurement precision and a better user experience. In part this is due to the stable design of the weighted, self-standing electrode. The electrode is keyed to the 24-well plates. This ensures repeatable placement that gives more consistent results, eliminating the need for multiple readings.
Both are also designed for hands-free operation. When properly positioned, the electrode will stand on its own in a single well of a well plate. This eliminates, or at least minimizes, the variability factors associated with user handling, making measurements more precise.

Both of the newer electrodes have a shielded cable that blocks radio frequency interference from electrical sources and cell phones.
The shorter tips on the STX4 electrode means you need less liquid volume in the wells to cover the tips than you needed when using the STX2-PLUS. When using expensive media, this saves resources.

The STX4 has replaceable electrode blades, which means the functional life of the electrode is much longer. When the blades age, simply replace them, not the electrode. Replacement blades are sold in packages of 3 sets. This feature makes the STX4 more cost-effective than all previous models. Changing the blades is easy. You can watch the video to see for yourself. (LINK)
Finally, the specially coated tip of the STX4 requires no chloriding, which was required for all the other EVOM™ electrodes. This saves you time. The STX4 is ready when you are. There’s no need for advanced cleaning procedures either.

The EVOM™ STX4 is WPI’s newest version of the electrode with improved and advanced features, and it is replacing the previous version (STX2-PLUS). This STX4 electrode is designed to be used with the new EVOM™ Manual and the EVOM3. With an adapter, it can also be used with the EVOM2 and the MilliCell® ERS2. Upgrade to the new STX4 TEER Measurement Electrode to improve your measurement precision, conserve resources and save time.


If you have any questions, contact us.