Automated TEER Measuring System EPITHELIAL PHYSIOLOGY The REMS AutoSampler automates measurements of electrical resistance of transepithelial, transendothelial or Caco-2 cell membranes being grown to confluence on microporous filters of high throughput screening (HTS) 24- and 96-well microplates. It is a PC-controlled tissue resistance measurement system that offers reproducibility, accuracy, flexibility, and ease-of-operation for this kind of measurement. Automated measurement of tissue resistance in cell culture microplates provides the important advantages of speed, precision, decreased opportunity for contamination and the instant availability of measured resistance data on a computer. These measurements are useful in applications such as drug bioavailability studies and studies on the mechanisms of drug transport. The main components of the REMS AutoSampler include: the robotic sampler that moves the electrode over each well of the microplate, the electrode which is located on the robotic arm, a base plate for the 24- and 96-well tray, a Windows-based data acquisition card, the REMS interface unit and the REMS software to operate the system on a Windows-based computer. The REMS AutoSampler automates TEER measurements previously made with WPI’s EVOM Epithelial Voltohmmeter. Automated tissue resistance measurements up to 20 kΩ can be performed on 24- or 96-well HTS microplates. Microplates presently supported include the Corning Costar HTS Transwell-24, Falcon HTS Multiwell insert systems, and Millipore Multiscreen™ CaCo 96-well plate. The REMS AutoSampler is designed to facilitate integration with other robotic systems. Special locating bars are installed on the REMS base platform that allow other system robots to place an HTS tray into a precise location on the REMS base. The REMS AutoSampler will automatically measure and record tissue resistance from a user-specified matrix of culture wells on the microplate. According to the specified sequence, the robotic arm moves over the identified wells taking TEER measurements. By means of a x-y-z locating system, the electrode-containing arm is positioned precisely REMS AUTOSAMPLER SPECIFICATIONS MEMBRANE RESISTANCE RANGE AC SQUARE WAVE CURRENT ELECTRODE POSITIONING ELECTRODE PERFORMANCE ELECTRODE ARM SPEED TYPICAL MEASUREMENT TIME 24-WELL SCAN PATTERN LINE VOLTAGE DIMENSIONS WEIGHT 0 to 2000 Ω and 0 to 20 kΩ +/- 20 µA @ 12.5 Hz Resolution in X, Y and Z: +/- 1 mm Repeatability in X, Y and Z: +/- 0.25 mm X- and Y-axis: 250 mm/sec Z-axis: 247.3 mm/sec 1 min, 10 sec Choice of any well pattern sampling User specified: 100/120 V or 220/240 V 53.5 × 43.7 × 37.1 cm (213⁄32 × 173⁄16 × 145⁄8 in.) 24 kg (52 lb) and reproducibly over each well. The ability of the REMS AutoSampler to reproducibly and precisely locate the electrode results in highly reproducible TEER measurements. TEER measurements are stored in the computer as the electrode moves from one well to the next. The Windowsbased software provides user-friendly features to acquire, display and store the tissue resistance measurements. The REMS electrode is very compact and robust in design. Each of two rod-shaped probes, 1.5 mm in diameter, consists of a pair of electrodes: one electrode for injecting current and the other for measuring the voltage. The use of two pairs of electrodes eliminates the error caused by the electrode-liquid interface. To take a measurement, the robot inserts one probe into the center of the filter well and the other into the opening slot of the 24- or 96-well plate. The use of AC current to measure resistance provides several advantages over DC current, including: ● Absence of offset voltages on measurements; ● There is a zero net current being passed through the membrane and, therefore, it is not adversely affected by a current charge; ● No electrochemical deposition of electrode metal. The REMS AutoSampler also features a rinse and calibration check station. If occasional rinsing of the REMS electrode is required it may be sent to a rinse station by pressing the rinse station button on the menu bar. SYS-REMS Automated Tissue Resistance Measuring System Includes robot sampler, base plate, data acquisition board; computer, display, keyboard, mouse; software for Windows XP or Vista; and electrode for either 24-well plate (Corning Costar HTS Transwell-24 or Falcon HTS Multiwell) or 96-well plate (Millipore Multiscreen CaCo) — SPECIFY WHEN ORDERING. ACCESSORIES REMS-24 REMS-96 REMS-96C Replacement REMS STX Electrode for 24-well HTS Plate Replacement REMS STX Electrode for MilliporeTM 96-well Plate Replacement STX Electrode for Corning 96-well plate Contact WPI for detailed information. World Precision Instruments 80 UK: Tel: +44 (0)1462 424700 • wpiuk@wpi-europe.com www.wpiinc.com Germany: Tel: +49 (0)30-6188845 • wpide@wpi-europe.com US: Tel: 941-371-1003 • sales@wpiinc.com