Methods and apparatus for detecting bacterial growth by

Abstract

The detection of bacterial growth or the performance of other interrogative processes in multiple sample vials is accomplished using a moving rack that selectively couples optical locations to an optical excitation and detection system. The apparatus includes a drive mechanism combining agitation of the culture vials with a sequential scanning of an array of optical fibers, preferably by a spectrophotometric excitation and detection system. Selection of each culture vial provides, for example, optical detection of bacterial growth by fluorescence or other spectrophotometric measurements. A rack for holding vials is preferably the only moving assembly, and requires no mechanical or electrical interconnection with the excitation and detection system for its operation. In general, the present invention relates to the optically indexed presentation of the optical guides, to many remote sample sites in the form of a geometric array at the interface between the moving culture vial rack assembly and the spectrophotometric excitation and detection system fixed to the body of the instrument. Methods of transmitting and receiving electromagnetic radiation to and from sample vials held in a movable rack include the steps of coupling the sample vials to an optical fiber and terminating the optical fiber at an optical coupling location. The rack is then moved to align at least one of the coupling locations with an excitation and detection system.