The present disclosure provides instruments and methods for detecting an analyte which are capable of exciting a plurality of luminescence labels and detecting light emitted therefrom. The instrument includes a filter carrier adapted for carrying a plurality of filter portion pairs, each pair related to a luminescence label and comprising a first filter portion for transmitting excitation light, and a second filter portion for transmitting emitted light. The first filter portion of a pair comprises a second filter portion of another pair. Also, the filter portions are arranged such that a pair can be brought into an operative condition whereby a first filter portion is in the excitation beam path and a second filter portion is in the emission beam path. The filter carrier and beam paths may be moved with respect to each other by a moving mechanism so as to bring a pair into operative condition.