A Perfusion Chamber for Cinemicrographic Studies

Most perfusion chambers hitherto described for time-lapse cinemicro-graphic studies of living cells have defects. Chambers of the type originally described by Pomerat (1953) provide good optical conditions and a shallow chamber but require some skill to manage and, being sealed with wax, tend to leak unexpectedly. This difficulty is overcome by the designs of Rose (1954) and Richter (1955) in which the chamber is formed by sand-wiching a rubber gasket between metal plates, but in these cases it is usually too deep to permit accurate focusing of the substage condenser at high magnifications.

The chamber described here is a compromise based on the above designs and an ingenious one proposed by Dick (1955). It can be made easily in a day or so in any workshop and in use it can be assembled in 5 min. with the minimum of skill. The construction is clear from the diagram. Dimensions can be adjusted to suit requirements. Our own chambers are 3x2m. (77x51 mm) with a chamber in. (32 mm) in diameter for use with i| in. (38 mm) square no. 1 coverslips. The channels running along the bottom of the perspex section act as ducts from the reservoirs to the chamber when all parts are clamped together, the bottoms of the canals and reservoirs being formed by the lower rubber gasket. The depth of our own chambers is 1-5 mm and this is capable of further reduction.

When the apparatus has been assembled it is filled by placing medium in one of the reservoirs and tilting so that all the air (if desired) is removed before the medium flows through into the second reservoir. To change the medium, fluid is added to the filling reservoir and withdrawn from the emptying reservoir. This operation can be performed by means of a Pasteur pipette inserted through a -in. hole in the top of the microscope incubator, which does not therefore have to be opened. When properly made and assembled the chamber cannot leak. A further advantage is that the well formed above the top coverslip can be filled with water for use with waterimmersion objectives of the type used in interference microscopes.

I wish to thank Mr. Ian McLardy for his technical skill in making the prototypes to my design.