Abstract: The present invention provides an optics assembly, a reflectometer, and a diagnostic device for providing quantitative measurement of optical radiation reflected from a sampling area on an assay matrix. The reflectometer includes an optical radiation source and a detector. The optical radiation source and the detector are mounted in a single plane. An optics assembly is configured to direct the illumination from the optical radiation source to the sampling area on the assay matrix and to direct the radiation diffusely reflected from the sampling area to the detector. The optics assembly is positioned over the face of the circuit board having the optical radiation source and detector mounted directly thereto. The present invention also provides a method for determining the presence of one or more selected analytes in a sample employing a plurality of sampling areas on one or more assay matrixes.

Abstract: An automatic liquid transfer system includes a horizontally translatable table and a vertically translatable set of pipettes. The table accommodates a titer tray having a multiplicity of receptacles to be filled, or holding liquid samples to be diluted, and a rack housing plural rows of disposable tips. During each cycle in a serial dilution process, a fresh set of tips are picked up by the pipettes and used to transfer liquid in a sterile manner from a sample or diluent source to a row of wells in the titer tray, or from one row to a succeeding row of wells where it is mixed with diluent. Thereafter, the tips are discharged back into the rack to maintain sterile conditions during the process. A sensor is provided on the machine to detect whether all of the tips in each set are disengaged and another set successfully picked up.