Abstract: A testosterone derivative of formula (I): where n is an integer in a range of from 1 to 10, and Y represents an activated or ready-to-be-activated group allowing formation of an amide bond with a primary amine of a molecule. Conjugates including the testosterone derivatives and a marker, methods for determining the concentration of testosterone in a biological sample, and methods for preparing the testosterone derivatives are also provided.

Abstract: The invention concerns a standard micro-component (4) for calibrating or standardizing fluorescence measuring instruments, comprising a substrate (1) whereon is arranged at least one thin film (2). The thin film (2) includes fluorescent components. At least one first zone (3) of null thickness is formed in the thin film (2), thereby exposing the substrate (1). The thin film (2) comprises at least one exposed zone (2a), such that first and second fluorescence levels are respectively defined in the non exposed part and in the exposed part (2a) of the thin film (2). The second fluorescence level is lower than the first fluorescence level. The standard micro-component (4) can also include a plurality of stacked thin films so as to define a plurality of fluorescence levels.