Patent ID: 7785902

Claim:
A method of analysis of an analyte in a mixture of biological and/or chemical components, comprising: a) contacting magnetic particles with the analyte to attach the magnetic particles thereto or using the analyte that is already attached to magnetic particles, the magnetic particles possessing the property of a non-linear dependence of the magnetization and magnetic induction on the strength of an external magnetic field, b) exposing the magnetic particles attached to the analyte to a magnetic field, c) recording a signal due to the magnetic induction produced by the magnetic particles as a result of their exposure to the magnetic field, d) generating quantitative data on the content of the analyte in the mixture being analysed from the value of the signal, wherein e) the magnetic field has a spectrum, and the spectrum is pre-set with spectral components at least at two frequencies, wherein the amplitude of at least one of the spectral components is chosen high enough to ensure a non-linear dependence of the magnetic induction on the strength of the magnetic field, and the signal is recorded at such a frequency that is a linear combination of the frequencies of the spectral components during the exposure of the magnetic particles to the magnetic field.