Dual-Superfusion Slice Chamber Insert

 

It is not only a new product; but a unique, worldwide patented idea to support extended survival of brain slices. This brand new improvement of slice chambers for electrophysiological recordings and/or in vitro imaging was developed by Prof. Dr. Norbert Hajos, D.Sc. (email: hajos@koki.hu). The Dual-superfusion Slice Chamber Insert is recommended for all types of slice recordings, but is indispensable for investigations where oxygen is a limiting factor of neuronal function, e.g. network oscillations (Hajos et al., European Journal of Neuroscience, Vol. 29, pp. 319-327, 2009).

 

 

 

 

 

Dual superfusion of submerged slices increases the vitality of cells as oxygen, as well as other materials, can freely and more effectively diffuse into the thick slices from both sides. In the most widely used slice chambers, where the slices are sitting on a glass cover slip, oxygenation and drug diffusion is achieved only from one side.

 

 

A chamber insert was created where slices sit on a mesh, and the shape of the insert supports laminar flow around the submerged slices ensuring better oxygenation. The mesh divides the chamber into two parts. Both the upper (above the mesh), and the lower (below the mesh) parts of the chamber are 2 mm in height. By using this type of chamber design the flow rate of the superfused solutions can be kept as low as 3-5 ml/min, while the oxygenation of the tissue can be maximally maintained.

 

The Dual-superfusion Slice Chamber Insert is 20 mm in outer diameter. This diameter was chosen because this way our product is compatible with the most popular brain slice chambers on the market. The mechanical drawing of the plexiglass insert is available for download. Bigger meshes will be introduced later in the same 20 mm outer diameter for human brain slices. Measurements of your existing brain slice chamber to be compatible with the Dual-superfusion Slice Chamber Insert are:

- the diameter of the internal center hole must be larger than 20 mm

- the effective depth of the internal center hole should be approximately 5 mm or more

 

The working (meshed) area of the stainless steel mesh is 7.2 by 7.2 mm.

 

A description of how to maintain slices in interface conditions is available for download.

 

A product leaflet of Dual-Superfusion Slice Chamber Insert is available for download.

 

A Frequently Asked Questions file about Dual-Superfusion Slice Chamber Insert is available for download.

 

 

Stainless steel mesh:

 

        Click on the picture to get it in full size

 

One piece of plexiglass insert:

 

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Plexiglass inserts with stainless steel mesh:

 

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Tips

 

Based on the experience obtained in Prof. Dr. Norbert Hajos' laboratory (Hajos et al., 2009, see above), the temperature and oxygenation of brain slices in the Dual-Superfusion Slice Chamber Insert can be controlled in two ways. Either the experiments should be done at room temperature, then only the flow rate of aCSF (Artificial CerebroSpinal Fluid) has to be set equivalently below and above the slices (e.g. using peristaltic pumps with at least three channels - two inlets and one outlet). Or in case the experiments are desired to be performed at a higher temperature, then not only the flow rate but the temperature as well should be maintained as equivalent as possible below and above the slices. To achieve this, a Dual-channel In-line Solution Heater is recommended, where the temperature of the two inlets is controlled in a single heater head to ensure the same temperature.

 

If you want to use the Dual-Superfusion Slice Chamber Insert in optimal conditions, the temperature of the two independent solution flows should be controlled. For this purpose any kind of 2-channel in-line solution heater, and a compatible temperature controller should be used. We recommend using the related products of Supertech Instruments. These are the Dual-channel In-line Solution Heater and the compatible Physiological - Biological Temperature Controller TMP-5x. They are an optimal choice because they work as a set, and are optimized for dual-superfusion survival method.

 

On the surface of the stainless steel mesh the effects of some unwanted electrochemical changes can be observed after 3 month of usage. If you notice such an effect, please replace the mesh in order to provide the optimal living conditions of your slices.

 

Some sterilizing gases used in the medical routine destroy the material of the plexiglass inserts chemically. Please take this aspect into account.

 

We offer the complete assembly "Plexiglass inserts with stainless steel mesh"; or its parts independently. The reason we offer separate parts is that the outcome of cleaning the assembly is in many cases uncertain (because of the impact the cleaning solution has on the plexiglass or the mesh), so it might be easier to simply replace them. New replacement parts are fully compatible with the existing parts of the assembly.