Investigation of interactions between biomolecules of differing types, attaches biomolecules to backlit biochip using chemical spacers, and includes measurements with total internal reflection

摘要

Investigation of interactions between biomolecules of differing types, comprising attaching biomolecules to a backlit biochip using chemical spacers, and measuring total internal reflection, is new. Biomolecules are attached to a backlit support (1), e.g. a biochip, with intermediate chemical spacers (S), holding them at a given clearance from it. Fluorophores are added to the solution, which with attachment of biomolecules of the first type to the biochip, or to biomolecules of the second type, become incorporated into molecules of the first type. The biochip is exclusively or additionally illuminated at an angle, causing total internal reflection inside it. Sample fluorescence intensity is measured with positional resolution. By comparison of measured values of reflected beam intensity and of fluorescence, the proportion of biomolecules of the first type attached specifically to biomolecules of the second type is determined. On the side facing the sample, the biochip is coated with a metal layer. Totally-internally reflected light causes surface plasmon resonance (SPR) in the metal layer. Phase and intensity measurement of the totally-reflected light, is carried out by ellipsometry, with positional resolution. These values are used in the comparison, to determine the proportion of attached biomolecules of the first type. The intensity of fluorescence is measured at various angles of incidence, and the results are used in the comparison. An independent claim is included for the corresponding measuring instrument arrangement.