The present invention relates to a device for conducting the identification and quantification of micro-organisms, e.g., bacteria in biological samples. More particularly, the invention relates to a system comprising a disposable cartridge and an optical cup or cuvette having a tapered surface; an optics system including an optical reader and a thermal controller; an optical analyzer; a cooling system; and an improved spectrometer. The system may utilize the disposable cartridge in the sample processor and the optical cup or cuvette in the optical analyzer.