Masking background fluorescence and luminescence in optical analysis of biomedical assays

Abstract

In a process for the quantitative optical analysis of fluorescently labelled biological cells , a cell layer on a transparent support at the bottom of a reaction vessel is in contact with a solution containing the fluorescent dye . The sensitivity of analytical detection can be considerably improved if to the fluorescent dye already present in addition a masking dye , which absorbs the excitation light for the fluorescent dye and/or its emission light , is added to the solution and/or if a separating layer permeable to the solution and absorbing and/or reflecting the excitation light or the emission light is applied to the cell layer at the bottom . The separating layer must be composed such that it has a high power of reflection for the luminescent light . Analogously, these process principles can also be used in receptor studies for the masking of the interfering background radiation in the quantitative optical analysis of fluorescently or luminescently labelled reaction components. In this case, a receptor layer at the bottom of a reaction vessel is in contact with a solution in which a fluorescent or luminescent ligand is dissolved. The sensitivity and accuracy of the analytical detection can be considerably improved here if a masking dye which absorbs the excitation light for the fluorescent dye and/or its emission light or the luminescent light is added to the supernatant . Instead of the masking dye in the solution or optionally as an additional measure, a separating layer permeable to the solution and absorbing and/or reflecting the excitation light and/or the emission light or the luminescent light can be applied to the cell or receptor layer at the bottom