Abstract: The excision of sample spots from a gel or membrane by pressing a cutting tool terminating in a hollow cylinder against the gel or membrane supported on a rigid surface is made more reliable by interposing a relatively pliable, intermediate layer on the side of the surface facing the gel or membrane. The pliability of the intermediate layer compensates for any irregularity or misalignment of the cutting edge of the cylinder relative to the gel or membrane.

Abstract: The excision of sample spots from a gel or membrane by pressing a cutting tool terminating in a hollow cylinder against the gel or membrane supported on a rigid surface is made more reliable by interposing a relatively pliable, intermediate layer on the side of the surface facing the gel or membrane. The pliability of the intermediate layer compensates for any irregularity or misalignment of the cutting edge of the cylinder relative to the gel or membrane.

Abstract: A controller (30) based chromatography system (2) especially designed for flexibility of operation with ease of use and an icon based control panel (32), has a number of function panels (34), each having a function key (36), one or more indicator indicia (40) in the form of icons, letters or numbers, and associated indicator lights (38). A switching valve (4) is used to provide a mixture of two or more solvents (6, 8) to a peristaltic pump (12). The cyclic nature of the pump and mixer can create a resonant condition resulting in poor quality information from the UV monitor (20). The system minimizes this by the judicious selection of the total cycle time T for the switching valve. This can be done using a random number manipulated in a manner to come up with each time T. Alternatively, an irrational number is combined with the pulsation frequency of the pump to create each time T.

Abstract: A fraction collector includes a base unit and a turntable rotatably mounted on the base unit for supporting a plurality of collection tubes. The upper horizontal surface of the base unit includes a receptacle which is disposed to collect fluids discharged onto the base unit. The turntable is enclosed and includes a discharge port which is aligned over the receptacle when the turntable is mounted on the base unit. In this way, fluids which are intentionally or unintentionally discharged into the turntable will be collected in the receptacle 46. Receptacle 46 also includes a discharge port which may be connected to a disposal site, typically by flexible tubing.