主要规格及技术指标

The model OC-725C Oocyte clamp is designed for two-electrode, whole-cell voltage clamping of Xenopus oocytes, as well as for other large cells and cell structures such as squid axons. The system mainly includes OC-725C oocyte clamping amplifier, Digidata 1440A (Digital analog/ analog-digital converter) and acquisition software. All these hardware and software are used to complete the double signal acquisition and analysis of electrode voltage clamp experiment.
The OC-725C is comprised of three functional channels: A high impedance voltage sensing channel with capacity compensation and input offset to measure membrane potential, a current sensing channel with bath clamp to clamp the bath and measure the membrane current, and a high voltage amplifier to deliver the clamping current. The complete voltage clamp system consists of the OC-725C, the voltage recording probe with electrode holder, the current sensing bath  probe with silver wire electrodes, and the current cable with electrode holder.
 OC-725C型卵母细胞钳模型设计用于非洲爪蟾卵母细胞的两电极全细胞电压钳，以及其他大型细胞和细胞结构（如鱿鱼轴突）。该系统主要包括OC-725C卵母细胞钳位放大器，Digidata 1440A（数字模拟/模数转换器）和采集软件。所有这些硬件和软件均用于完成电极电压钳实验的双信号采集和分析。
OC-725C包含三个功能通道：具有容量补偿和输入偏移量的高阻抗电压传感通道，用于测量膜电位；具有浴钳的电流传感通道，用于钳位浴并测量膜电流；以及高压放大器提供钳位电流。完整的电压钳系统包括OC-725C，带电极支架的电压记录探头，带银线电极的电流感应浴探头以及带电极支架的电流电缆。

主要功能及特色

1) High Voltage Compliance: The OC-725C combines high AC and DC gains and a voltage compliance of ±180 V to insure fast, nonsaturating clamp performance under nearly any condition. The AC clamp gain is variable up to 2000. An additional DC gain may be employed for high conductance cells or leaky oocytes. The amplifier provides two clamping speeds: Slow and Fast. Slow mode is used for screen oocytes, or in cases where rapid response is not required. Fast mode is used for precise clamping of fast whole cell electricity.
2) Bath Clamp Headstage: Its current measurement has 3 ranges, which can make small current amplify to the level of analysis and large current (up to 1 mA) does not saturate the amplifier. The bath pliers probe can accurately measure the bath fluid current and the bath potential is clamped to 0 simultaneously. There is no need to compensate the series resistance due to the presence of the bath pliers probe.
3) Dual Oocyte Studies: Studies involving two oocytes in a common bath requires   two clamp amplifiers. The bath clamp headstage cannot provide effective clamping because it cannot separate the individual currents from the combined current appearing in the bath. The OC-725C solves this problem by the application of an internal switch permitting measurement of the current in series with the current electrode instead of in the bath. Additionally, an optional differential voltage headstage is available which subtracts the voltage drop across the series resistance in the bath.
4) Voltage Headstage Probe: The voltage measuring headstage is a single-ended, high-impedance probe. Its small size, convenient mounting rod, and two meter   cable make for easy attachment to a micropositioner. A supplied electrode holder with a 2 mm jack mounts directly on the headstage.
5) Voltage and Current Meters: Independent meters provide simultaneous displays of membrane voltage Vm and membrane current Im. To assure proper impalement of the current electrode, the current meter displays membrane potential, Ve, from the current electrode before the clamp circuit is activated.
1）高电压顺从性：OC-725C兼具高AC和DC增益以及±180 V的电压顺从性，以确保几乎在任何条件下均具有快速，不饱和的钳位性能。交流钳位增益最多可更改为2000。对于高电导细胞或卵母细胞泄漏，可以使用附加的直流增益。放大器提供两种钳位速度：慢速和快速。慢速模式用于筛选卵母细胞，或在不需要快速响应的情况下使用。快速模式用于对快速的全细胞电流进行精确钳制。
2）浴夹探头：其电流测量范围为3个范围，可以使小电流放大到分析水平，大电流（高达1 mA）不会使放大器饱和。浴钳探头可以精确地测量浴液电流，并且浴电位同时被钳位为0。由于浴钳探针的存在，因此无需补偿串联电阻。
3）双卵母细胞研究：在公共浴池中涉及两个卵母细胞的研究需要两个钳位放大器。浴夹头架无法提供有效的夹紧力，因为它无法将单个电流与浴中出现的组合电流分开。 OC-725C通过使用内部开关解决了这个问题，该开关允许测量与电流电极串联而不是在电解槽中的电流。此外，还提供一个可选的差分电压探头，可以减去浴中串联电阻两端的电压降。
4）电压探头：电压测量探头是单端，高阻抗探头。它的体积小，安装杆方便，两米长的电缆易于安装到微型定位器上。附带的带有2 mm插孔的电极支架直接安装在探头上。
5）电压和电流表：独立的仪表可同时显示膜电压Vm和膜电流Im。为了确保正确插入电流电极，电流表在钳位电路激活之前会显示电流电极的膜电位Ve。

主要附件及配置

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