Apparatus for automatically processing magnetic solid phase reagents

Claim 1

An automatic apparatus for use in assays for separating magnetic particles from a liquid phase, the apparatus comprising: a plurality of reaction vessels for holding magnetic particles dispersed in a liquid phase, a reaction vessel mounting wheel for moving the plurality of reaction vessels in sequence past at least one processing position, probe means for dispensing liquid into and withdrawing liquid from the plurality of reaction vessels, a reaction monitoring arm mounted for relative movement with respect to the reaction vessel mounting wheel and to be positioned with its periphery adjacent any of the plurality of reaction vessels, a detector positioned on the reaction monitoring arm radially outside of the plurality reaction vessels, the reaction monitoring arm being operable to direct a beam of interrogating radiation through each plurality of reaction vessles to the detector, and coupling means coupled to the reaction monitoring arm for selectively positioning a first magnet adjacent the location of the beam of interrogating radiation, but spaced therefrom by the distance separating adjacent plurality of reaction vessels on the reaction vessel mounting wheel.