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ENDOHM-24G

ENDOHM-24G

EndOhm for 24mm and Costar Snapwell Culture Cups (6 wells per plate)



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Overview

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Endohm Instruction Manual
/ Download as PDF

For TEER measurement of epithelial and endothelial cell cultures

 

  • The new EndOhm chamber upper mount is made of polycarbonate and unaffected by alcohol
  • The glass chamber is easier to clean and more crack resistant than the prior version
  • Compatible with original EVOM, EVOM2™ EVOM3 meters
  • Adjustable apical electrode height
  • Crystal clear glass chamber allows visualization of apical electrode positioning
  • New insert holder with 120º tri-supports for three leg inserts
  • Three sizes cover a range of well cup sizes from a variety of manufacturers

Options

Part # Description
ENDOHM-24G-SNAP EndOhm for 24mm and Costar Snapwell Culture Cups (6 wells per plate)
ENDOHM-12G EndOhm for 12mm Culture Cups (12 wells per plate)
ENDOHM-6G EndOhm for 6mm Culture Cups (24 wells per plate)


Benefits

  • Stability and reproducibility superior to the STX2 electrodes to 1% tolerance
  • Can be used with 6, 12 or 24 well plates with removable inserts
  • Symmetrical electrode pattern disperses test current uniformly
  • Tri-leg supports offer mechanical stability and the membrane is held parallel to the electrodes (G version)
  • Simple test procedure to verify electrode performance

Applications

  • TEER measurement for removable culture cup systems using EVOM2™ meters for endothelial and epithelial cell cultures

TEER measurement in individual cups

Using WPI’s EVOM2™ 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.

Make more precise measurements with Endohms

Endohm’s symmetrically opposing 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 from 150?Ω (when using WPI’s hand-held STX2 electrodes) to less than 5 Ω. With Endohm’s fixed electrode geometry, variation of readings on a given sample is reduced from 10-30 Ω with STX2 electrodes (depending on the experience of the user) to 1-2 Ω. 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 capacitance are largely eliminated. Endohm together with EVOM2™ offers the most accurate and economical endothelial ohmmeter now available. To date, cups from Corning, Millipore, Nunc, Greiner and BD Falcon have been tested. Endohm chambers may be sterilized with EtO, alcohol or a bactericide; not autoclavable.

 

 

Specifications

Compatibility Charts

 

The ENDOHM-24SNAP is compatible with the following chambers:

Corning Millipore  Membrane Material Pore Size (µm)
3407   Polycarbonate 0.4
3801   Polycarbonate 0.4
3802   Polycarbonate 3.0
3412 PIHT30R48* Polycarbonate 0.4
3414   Polycarbonate 3.0
  PITT03050 Polycarbonate 3.0
3428   Polycarbonate 8.0
3450   Polyester 0.4
3452   Polyester 3.0 
3491   Collagen 0.4
3492   Collagen 3.0
  PICMORG50 Organotypic Insert 0.4
  PIHA03050 HA Insert 0.45
  PIHP03050 PCF Insert 0.4
  PICM03050 HA mixed cellulose esters 0.4 
  PIHT30R48* PET Insert 0.4
  PIRP30R48* PET Insert 1.0
  PISP30R48* PET Insert 3.0
  PIMP30R48* PET Insert 5.0
  PIEP30R48* PET Insert 8.0

* The tri-support legs must be balanced correctly so that the filter is parallel to the electrodes.

Nunc Pore size (μm) Culture area (cm²)
140640 0.4 3.14
140642 3.0 3.14
140644 8.0 3.14
140660 0.4 4.1
140663 3 4.1
140668 8 4.1

 

ThinCertTM Membrane material Pore size [µm] Pore density [cm-2] Optical membrane properties TC surface treatment/Sterile Multiwell plates/ThinCertTM per box
657640 PET 0.4 1 x 108 translucent +/+ 4/24
657641 PET 0.4  2 x 106 transparent +/+ 4/24
657610 PET 1.0  2 x 106 transparent +/+ 4/24
657630 PET 3.0  0.6 x 106 transparent +/+ 4/24
657631 PET 3.0  2 x 106 translucent +/+ 4/24
657638 PET 8.0  0.15 x 106 translucent +/+ 4/24

 

Millicell Pore size (μm) Qty/pk
MCHT06H48 0.4 48
MCRP06H48 1.0 48
MCSP06H48 3.0 48
MCMP06H48 5.0 48
MCEP06H48 8.0 48

 

BD Falcon Membrane material Pore size [µm] Pore density [cm-2] Optical membrane properties TC plate (#wells)
353090 PET 0.4 2.0 ± 0.2 x 106 transparent 6
353102 PET 1.0 1.6 ± 0.6 x 106 transparent 6
353091 PET 3.0 8 ± 2 x 105 transparent 6
353093 PET 8.0 6 ± 2 x 104 translucent 6
353493 PET 0.4HD 100 ± 10 x 106 translucent 6
353092 PET 3.0HD 2.0 ± 0.2 x 105 translucent 6

 

Accessories

Citations

Sheller, R. A., Cuevas, M. E., & Todd, M. C. (2017). Comparison of transepithelial resistance measurement techniques: Chopsticks vs. Endohm. Biological Procedures Online, 19, 4. http://doi.org/10.1186/s12575-017-0053-6

Srinivasan, B., Kolli, A. R., Esch, M. B., Abaci, H. E., Shuler, M. L., & Hickman, J. J. (2015). TEER measurement techniques for in vitro barrier model systems. Journal of Laboratory Automation, 20(2), 107–26. http://doi.org/10.1177/2211068214561025

TORRES, R., PIZARRO, L., CSENDES, A., GARCÍA, C., LAGOS, N., Pasdar, M., … Roskelley, C. (2007). GTX 2/3 EPIMERS PERMEATE THE INTESTINE THROUGH A PARACELLULAR PATHWAY. The Journal of Toxicological Sciences, 32(3), 241–248. http://doi.org/10.2131/jts.32.241

Patil, R. V., Han, Z., Yiming, M., Yang, J., Iserovich, P., Wax, M. B., & Fischbarg, J. (2001). Fluid transport by human nonpigmented ciliary epithelial layers in culture: a homeostatic role for aquaporin-1. American Journal of Physiology - Cell Physiology, 281(4).

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