TEER Measurement in Individual Endothelial Cell Cultures Cups
WPI's EndOhm chambers were designed for making TEER measurement of endothelial cell cultures in individual cups. The EndOhm chambers feature:
- Compatible with EVOM²
- Improved accuracy of 1-2Ω
- Accommodates 6mm, 12mm, 24mm cups and Costar Snapwell cup
- Sterilized with EtO, alcohol or a bactericide
Using WPI's EVOM² resistance meter, EndOhm chambers provide reproducible resistance measurements of endothelial tissue 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. Endohm's symmetrically apposing circular disc electrodes, situated above and beneath the membrane, allow a more uniform current density to flow across the membrane than with STX2 electrodes. The background resistance of a blank insert is reduced from150Ω (when using WPI's hand-held STX2 electrodes) to less than 5Ω.
With EndOhm's fixed electrode geometry, variation of readings on a given sample is reduced from 10-30Ω with STX2 electrodes (depending on the experience of the user) to 1-2Ω. Compared with other resistance measurement methods, EndOhm with EVOM² offers a much more convenient and economic solution to "leaky tissue" measurement. Because of the uniform density of the AC square wave current from EVOM², errors owing to electrode polarization or membrane capacitanceare largely eliminated.
EndOhm, together with EVOM², offers the most accurate and economical endothelial ohm meter now available. To date, cups from Costar, Millipore, ICN Biomedicals and Falcon have beenchambers may be sterilized with EtO, alcohol or a bactericide (like Cidex). They are not autoclavable.