自動組織電阻測量系統 REMS

型號：SYS-REMS

• 電腦控制的組織電阻測量系統。
  
• 適用於跨上皮細胞膜、跨內皮細胞膜、Caco-2細胞膜。
  
• 高再現性、精確、靈活易操作。
  
• 搭配24孔盤或96孔盤使用。

自動化跨上皮電阻（TEER）測量系統

REMS自動採樣裝置，可自動測量在高通量(HTS) 24微孔盤和96微孔盤的微孔過濾器上，正在生長至滿溢(confluence)的跨上皮、跨內皮、或Caco-2細胞膜電阻。此裝置為PC控制的組織電阻測量系統，提供高再現性、準確性、靈活性，且易於操作。在細胞培養的微孔盤中自動測量組織電阻，提供快速、精確的重要優勢；降低汙染機會、即時在電腦上獲得所測電阻資料。這種測量方式在藥品生體利用率研究和藥物轉運機制研究中十分有用。REMS自動採樣系統包和以下組件：(1) 機器人採樣器：於微孔盤各培養杯間移動電極；(2) 置於機械手臂上的電極； (3)底板：24孔和96孔托盤用；(4) Windows作業系統用資料擷取卡；(5) REMS介面單元；(6) REMS軟體：搭配Windows作業系統電腦使用。

自動測量並記錄組織電阻

REMS自動採樣裝置過去是搭配WPI開發的EVOM2跨膜電阻儀來執行自動TEER測量。自動電阻測量最大可達20歐姆，適用於24孔或96孔HTS微孔盤。目前可支援的微孔盤包含Corning Costar HTS Transwell-24、Falcon HTS Multiwell insert systems、和Millipore Multiscreen™ CaCo 96-well plate。REMS自動採樣裝置特別設計可與其他機器人系統整合，REMS基底平台上安裝的特殊定位桿，讓其他系統機器人可以將HTS托盤放置在REMS平台上精確位置。REMS自動採樣裝置將自動測量並記錄用戶自訂微孔盤培養杯矩陣的組織電阻。根據指定順序，機械手臂在培養杯上移動並進行TEER測量。藉由x-y-z軸定位系統方式，內含電極的手臂精確定位並在每個培養杯重複執行。ＲEMS自動採樣裝置能夠重複並精確定位電極，因此可以高度再現TEER測量。在電極移動到下一個培養杯時，TEER測量結果被儲存於電腦中。搭配Windows系統使用之軟體，人性化設計可擷取、顯示、儲存組織電阻測量。

緊湊而強勁的電極設計

REMS電極設計緊湊而堅固，兩個棒狀探針，直徑1.5mm內含一對電極：一個電極為注入電流，另一個為測量電壓。使用兩對電極可以消除由電極-液體介面引起的錯誤。測量時，機器人將一個電極插入filter well中心，另一個電極插入24孔盤或96孔盤的開口插槽。相對於使用DC電流，使用AC電流測量電阻有以下優點：

• 測量時無補償電壓(offset voltages)。
• 0淨電流通過細胞膜，因此充電電流(current charge)不會有不良影響。
• 電極金屬無電化學沉積

沖洗與校正台

REMS自動採樣裝置具有一個沖洗與校正檢查站。若偶爾需要沖洗REMS電極，可以按下菜單選單上的沖洗台按鈕將其送至沖洗台。若裝配帶合成膜的校正細胞，沖洗站也可作為校正檢查台用。使用此模仿流體中的上皮細胞膜滿溢(confluent)電阻的校正細胞，提供快速而有效測試，用以確認REMS完全啟動開機並在操作期間檢查其功能性。

以下孔盤可用於REMS系統：

Automated TEER Measuring System

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.

Automatically measure and record tissue resistence

The REMS AutoSampler automates TEER measurements previously made with WPI’s EVOM2 Epithelial Voltohmmeter. Automated tissue resistance measurements up to 20 ohm 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 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 Windows-based software provides user-friendly features to acquire, display and store the tissue resistance measurements.

Compact, robust electrode

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

Rinse and calibration station

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. The rinse station can also function as a calibration check station when fitted with a calibration cell containing a synthetic membrane. The use of this calibration cell, which mimics a confluent epithelial membrane’s resistance in fluid, provides a quick and effective test to determine when the REMS measurement system is fully initialized following start-up and to check its functionality during operation.