Abstract: A fitting assembly for coupling tubing to a device having a sealing surface is provided. The fitting includes a ferrule for seating against the sealing surface. The ferrule has a head. The ferrule is formed from a first material. A reusable collar having a bevelled rear surface and an inner surface is provided. The inner surface has a ring for gripping the tubing. The collar is formed of a second material that may differ from the first material and may be malleable. A coupler engages the head of the ferrule to push the ferrule against the sealing surface. The coupler has a ramped inner surface for engaging the rear surface to push the collar against the head of the ferrule. The coupler compresses the collar radially to grip the tubing.

Abstract: A low carryover fitting assembly for coupling tubing to a device having a sealing surface is presented. The fitting includes a ferrule having a conical head for seating against the sealing surface. The ferrule has a conical tail. The ferrule has an axial passage that is substantially equal in diameter to the inside diameter of the tubing. The fitting includes a sleeve having a ramped inner surface that is greater in inside diameter towards the forward end of the sleeve and smaller in inside diameter towards a rearward end of the sleeve. The fitting also includes a coupler, such as a coupling nut. The coupler has a front surface that engages the head of the ferrule to push the head against the sealing surface. The nut has an inner ramp or shoulder that engages the sleeve to urge the sleeve towards the head of the ferrule when the coupling nut is tightened. The tubing is compressed between the tail of the ferrule and the tapered section of the sleeve.

Abstract: An automatic chemistry system having a wheel for mounting reaction vessels is provided with a programmable permanent magnet which is selectively positioned adjacent a reaction vessel to separate magnetizable particles in the vessel from the vessels liquid contents. This facilitates performing heterogeneous immunoassays.