The transportation, manipulation, positioning and detection of single biomolecules with magnetic particles requires knowledge of different scientific areas. Biochemical skills are needed for the functionalisation of the sample surface and the investigation of bonds between biomolecules. Physical knowledge is required for the preparation of the chips, the calculation of magnetic field configurations or the detection of magnetic markers with TMR sensors. This chapter provides the theoretical background for all areas that are used in this thesis. It starts with basics about the used biomolecules and their bonds, goes on about magnetic field configurations and finishes with some TMR theory.