A portable, electrically-powered point-of-care instrument typically used to scan an immunoassay reagent vehicle (e.g., test strip, cassette, or card) after exposure to a clinical specimen, to provide a quantitative and/or qualitative in vitro determination of cells and/or markers, chemical substances and/or biological markers in a clinical specimen. The instrument detects fluorescent markers that result from the immunological reaction between the reagents and the specimen and uses a spectrophotometric method to measure the absorbance of chemical and/or biological markers. It is mostly used for rapid in vitro diagnostic measurements at the point-of-care or in the laboratory.