 |
|
The Organ Bath Type 813 according to Steiert, is designed for measuring intracellular action potentials as well as contractile force response of heart muscle preparations. It consists of the temperature controller DC, a perspex chassis, the organ vessel, the flow heater and the holder for the force transducer HSE-HA F30 (F10), with a precision micrometer Vernier control.
The solution is thermostabilized by a DC voltage driven direct flow heater mounted under the perspex platform below the organ vessel. The DC Temperature Control Unit, Type 319/1, in combination with the Peristaltic Pump, is essential to ensure a low level of radiated electrical interference.
The Temperature Controller DC has been specially developed for controlling the temperature of the solution flow to the Steiert Organ Bath. In designing the controller special attention has been paid to ensure a low level of radiated electrical interference. The heating circuit (temperature controller) is extremely thoroughly decoupled from the perfusate circuit. This provides excellent facilities for interference-free recording of intracellular action potentials using glass microelectrodes.
The solution tube of the heating element is of stainless steel, and is therefore inert and corrosion resistant. The solution flow is continuously running through the organ chamber driven by the first peristaltic pump channel or from the hydrostatic pressure (500 to 1000 mm H2O). At the end of the organ chamber, there is a suction tube which can be adjusted in its height to regulate the bath volume. This tube is linked to the second pump channel. Thus it is possible to recirculate the solution or to store it in a waste bottle.
The microelectrode for recording intracellular action potentials (AP) is connected to the PLUGSYS Microelectrode Amplifier MEA. The APsignal can be differentiated using the module DIF-S. The Isometric Force Transducer F30 or F10 is connected to a PLUGSYS Transducer Amplifier TAM-A. The organ bath together with the manipulators and preamplifier headstage are mounted on a vibration free table mainly but not necessarily equipped with a Faraday Cage. A stereomicroscope and a cold light lamp are also requested.
Switching between different solutions can be done with a selection valve at the inlet of the peristaltic pump. The volume of the heater is less than 1 ml, so it is possible to change very quickly from one solution bottle to another. Because of the direct heating system, there is no temperature difference in the bath.
|
The diagram to the left illustrates the arrangement of the organ bath. It shows the force measuring system with the Force Transducer (F30), the slider for preload adjustment, and the bath block with the chamber for the heart muscle preparation. The various parts of the apparatus are made mainly from Plexiglas or stainless steel and are therefore largely inert and corrosion resistant. |
|
Electrophysiology studies on papillary muscle or Purkinje fibre need electrical stimulation. To reduce the interference of the stimulation impulse with the intracellular action potential, the stimulation must be located exactly. For stimulation a Miniature Coaxial Stimulation Electrode is installed using ball joints. The electrode can therefore precisely and easily be place. The stimulation electrode is connected to the stimulator by means of an isolation unit. |
|
For easier preparation a special petri dish is available. This dish has a silicone disk for fixing the heart with the open left ventricle using needles. This allows to locate the muscle and to cut it easily out. The dish is also equipped with aeration capabilities, to keep the pO2 and the pH of the solution in the dish at the requested level. |
HUGO SACHS ELEKTRONIK-HARVARD
APPARATUS GmbH
Gruenstrasse 1 · D-79232 March-Hugstetten · GERMANY
Phone: +49 (0) 76 65 - 92 00-0 · Fax: +49 (0) 76 65 - 92
00-90