A holder for polygonal cross-section cuvettes is provided. The holder comprises a handle having and lying on an axis, and a holding plate connected to and extending radially from the handle. The holding plate is formed with a plurality of apertures each having a periphery. The periphery is formed with a plurality of notches corresponding in number and arrangement to the longitudinally directed edges of a polygonal-section cuvette. Inwardly concave portions are formed between the notches and connect the same in such a manner that a cuvette inserted in an aperture is held only at its longitudinally directed edges which engage only the notches. A supporting plate is also provided. This support plate is connected to the handle and spaced from and generally parallel to the holding plate in such a manner that a cuvette inserted in an aperture stands on the support plate.
A method for measuring the presence or concentration of an analyte in a sample by spectrophotometry: providing an open top cuvette having a sample with an analyte to be measured; providing a light source and a detector for detecting emitted light; taking at least two measurements that includes: (i) directing at least two beams of light from the light source to different locations on the cuvette; (ii) passing the at least two beams through the cuvette at their respective locations and through the sample to be measured; and (iii) measuring at least two respective emitted light beams with the detector; and comparing the at least two emitted light beams to determine if: all the emitted light beams should be disregarded; one or more of the emitted light beams should be disregarded; or the sample absorbances should be averaged. In a preferred embodiment, the method includes taking at least three measurements. In another preferred embodiment, the spectrophotometry is absorption spectrophotometry, and the method is performed on a diagnostic analyzer.
