Abstract: This invention concerns a spectroscopic method, apparatus for determining whether a component is present in a sample. In one aspect, the method includes resolving a model of the spectral data separately for candidates from a set of predetermined component reference spectra, and determining whether a component is present in the sample based upon a figure of merit quantifying an effect of including the candidate reference spectrum corresponding to that component in the model.

Abstract: A kit for use in a multiplex assay, the kit including a dye set consisting essentially of a plurality of dyes and an association of each dye to a reference concentration. The dye set has been selected such that, using surface enhanced resonant Raman spectroscopy, each dye of the set is identifiable at better than 90% sensitivity and 90% specificity in the presence of any other dye of the set throughout a range of concentrations of each of the two dyes from 0.6 to 1.5 of the respective dye's reference concentration. In one embodiment, the dye set consists of 10 of the following dyes: JOE, Rhodamine Green, ATTO520, BODIPY FL, BODIPY TMR-X, FAM, HEX, Cy3, Cy3.5, TAMRA and TYE563. The invention also concerns a multiplex assay including the set of dyes, apparatus for carrying out the multiplex assay and a method of selecting the set of dyes.

Abstract: This invention concerns a method of calibrating spectroscopy apparatus including illuminating a reference sample, identifying spectrum from light emitted from the sample and calibrating the spectroscopy apparatus based upon the spectrum, wherein the reference sample has been dried. The invention also concerns a reference sample for use in this method and a kit including such a reference sample. The reference sample may be lyophilised dye labelled oligonucleotides.