The letters "E P C" stand for Extracellular Patch Clamp, the method introduced by Neher and Sakmann (1976) for recording the currents in a small patch of membrane under voltage clamp technical advances have occurred, most notably the discovery of the 'gigaseal' by E. Neher (1981), which have made the words extracellular and patch excessively restrictive in describing this instrument. Based on the excellent design of the EPC 7 improvements and extensions were made which make the EPC 8 a worthy successor of the EPC 7. In comparison to the EPC 7 the holding potential range is increased to +/- 500 mV and a new low gain range allows to measure currents up to 2 µA. A fast current-clamp mode is introduced, which allows better follow of rapid changes in membrane potential, such as in neuronal action potentials.

The EPC 8 can be controlled manually like the EPC 7 by use of the knobs and switches on the front panel, but most of its functionality can also be controlled by use of a computer via appropriate hardware.

The EPC 8 is adapted for use with LIH 8+8 and PATCHMASTER, but it can also be used with other data acquisition hardware and software.

The following different hardware configurations of a computer controlled EPC 8 system are possible:

Besides the computer one of the following hardware is required to control the EPC 8:

Establish software control by using PATCHMASTER, PULSE or TIDA in conjunction with the LIH 8+8 or ITC-18 or write your own acquisition software for LIH 8+8 or any other 2 x 16 bit parallel digital I/O board.

The documentation about control of the EPC 8 via LIH 1600 is included with the EPC 8 delivery volume thus allowing the use of this patch clamp amplifier together with your own programmed data acquisition software. So anybody can use this patch clamp amplifier with his own data acquisition software.

Manual control by use of the knobs and switches on the front panel

Digital control of the following functions by use of a computer via appropriate hardware:

'Phase tracking': the 'dithering' of the external resistance and of the capacity can be controlled by the computer.

Read the settings of the above mentioned parameters which are set manually on the front panel, except 'phase tracking'

• Manual control by use of the knobsand switches on the front panel
• Digital control of the followingfunctions by the use of a computer:
  Gain, Mode of the EPC 8
  (Voltage-clamp, Current-clamp etc.), Filter, 'Phase tracking'
• Parameters which are manually set on the front panel (except 'Phase tracking') can be read by the software.
• Holding potential range of +/-500 mV +/-200 mV pipette offset
• A low gain range allows currents up to 2 µA Built-in 'phase tracking' capabilities
• Variable hardware filters
• C-Slow compensation (0-1000 pF, calibrated)
• 100-130 V AC or 200-260 V AC switchable

• Holding potential range is increased to +/- 500 mV
• Pipette Offset compensation is increased to +/- 200 mV
• A fast current clamp mode is introduced, which allows better follow of rapid changes in membrane potential, such as in neuronal ction potentials
• Fast current clamp is also possible in the low gain range
• RS compensation and C-Fast cancellation are active in current clamp mode
• A new low gain range allows measurement of currents up to 2 mA.
• Only one current monitor output with a variable 7-pole Bessel filter in 12 steps: 0.1, 0.3, 0.5, 0.7, 1, 3, 5, 7, 10, 20, 30 kHz and FULL (Full with a 3-pole Bessel filter)
• C-Slow compensation is increased (0-1000 pF, calibrated)
• Built-in 'phase tracking' capabilities according to Fernandez, by use of 'dithering' an additional resistor in series with the bath electrode or an additional capacity in the C-fast circuit.