A scanning system for detection and discrimination of a plurality of targets in each of a plurality of samples, each target bearing a distinct fluorescent label, said scanning system comprising: a sample plate with a planar array of sample wells disposed therein; a scanning head comprising: (i) a light source actuatable to supply excitation light at a plurality of excitation wavelengths, each of said excitation wavelengths selected to excite one of said fluorescent labels; (ii) a plurality of multiband emission filters, each arranged to simultaneously receive emission light emitted by two or more of said fluorescent labels upon excitation of said labels by said excitation light, and to pass said emission light so received in individually distinguishable wavelength bands, each said wavelength band including emission light from one of said fluorescent labels; and (iii) a single separate detector for each said multiband emission filter, wherein the detector is a non-imaging sensor that converts light impinging thereon to a measurable signal, said detector arranged to receive emission light passing through said multiband emission filter; and drive motors or mechanisms for causing translational movement of said scanning head over each of said sample wells in succession, wherein different multiband emission filters pass light in different combinations of wavelength bands, the combinations do not contain any duplicate wavelength bands between the different multiband emission filters, and said plurality of multiband emission filters collectively passes light emitted by all of said fluorescent labels. a sample plate with a planar array of sample wells disposed therein; a scanning head comprising: (i) a light source actuatable to supply excitation light at a plurality of excitation wavelengths, each of said excitation wavelengths selected to excite one of said fluorescent labels; (ii) a plurality of multiband emission filters, each arranged to simultaneously receive emission light emitted by two or more of said fluorescent labels upon excitation of said labels by said excitation light, and to pass said emission light so received in individually distinguishable wavelength bands, each said wavelength band including emission light from one of said fluorescent labels; and (iii) a single separate detector for each said multiband emission filter, wherein the detector is a non-imaging sensor that converts light impinging thereon to a measurable signal, said detector arranged to receive emission light passing through said multiband emission filter; and (i) a light source actuatable to supply excitation light at a plurality of excitation wavelengths, each of said excitation wavelengths selected to excite one of said fluorescent labels; (ii) a plurality of multiband emission filters, each arranged to simultaneously receive emission light emitted by two or more of said fluorescent labels upon excitation of said labels by said excitation light, and to pass said emission light so received in individually distinguishable wavelength bands, each said wavelength band including emission light from one of said fluorescent labels; and (iii) a single separate detector for each said multiband emission filter, wherein the detector is a non-imaging sensor that converts light impinging thereon to a measurable signal, said detector arranged to receive emission light passing through said multiband emission filter; and drive motors or mechanisms for causing translational movement of said scanning head over each of said sample wells in succession, wherein different multiband emission filters pass light in different combinations of wavelength bands, the combinations do not contain any duplicate wavelength bands between the different multiband emission filters, and said plurality of multiband emission filters collectively passes light emitted by all of said fluorescent labels.