EVOM STX4 Electrode

Overview

Electrode for EVOM3 and EVOM™ Manual with Replaceable Blades Ensures Stable Measurements

The STX4 electrode is the most recent version of chopstick electrode for the EVOM3 and EVOM™ Manual  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.

Features

• Electrode blades are replaceable. Over a period of use (after months or years) when the electrodes may have formed deposits from media or samples and may start showing reading instability, you may change the blades without having to replace the entire electrode.

  NOTE: Regular or daily cleaning after use will extend the functional life of the electrode blades.

• The electrode tip is specially coated and does not need to be chlorided with bleach or sodium hypochlorite for proper functioning, and it is not affected by chloriding either. Chloriding was critical for the previous model (STX2-PLUS electrodes) to maintain its functionality.

• The electrode tip (active sensing area) of STX4 is shorter than the STX2-PLUS. Being specially coated, it does not need to have large area as STX2-PLUS. Therefore, the STX4 electrode requires less apical (top of the insert) and basolateral liquid (media) volumes than STX2-PLUS to keep the electrode tips fully immersed and able to provide stable TEER measurement read outs.

• 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. This allows hands-free operation which further improve measurement precision.

• 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, and its flexible design is susceptible to the electrode tilting, which changes the gap between the two electrode blades during measurement. Capturing a steady and consistent value within the same sample group using an STX2 or STX3 is challenging. STX2 or STX3 users generally take multiple measurements of the same sample and use an average when using these electrodes. With the STX4 electrode, multiple measurements of the same sample is not required.

• The STX4 electrode has a shielded cable, and even the metal body of the electrode is tied to the shielding mechanism. By minimizing or eliminating electrical and cell phone interference, the shielding ensures that the TEER measurement and read outs are stable (do not fluctuate) and are unaffected by interference.

Benefits

• Replaceable blades – This new STX4 electrode has replaceable electrode blades.

• 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.

• Hands-free operation – The STX4 electrode fits perfectly in 24-well hanging transwells cell culture well plates and can stay hung on top of these transwells, allowing for hands-free operation.

• Greater precision – The STX4 electrode offers better TEER measurement precision, because it eliminates the variability factors resulting from change in electrode spacing and positioning as seen with STX2 electrode.

• 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.

Key STX4 Improvements Over STX2-PLUS

• Save resources, because the STX4 needs less liquid volumes.

• Save time, because the STX4 nees less maintenance. No chloriding is required.

• The STX4 is more cost-effective in the long run, because the electrode blades are user replaceable.

Refer to the table below for details (Differences and Similarities between STX4 and STX2-PLUS)

Related Product

EVOM Manual TEER Measurement Device