The majority of prokaryotic and eukaryotic cells can interact with a wide range of nano- and microparticles and films. The modified cells usually maintain their viability, but the presence of foreign material on their surfaces, in protoplasm or in intracellular organelles can provide additional functionalities. Cells modified using different procedures can be employed as whole-cell biosensors, whole-cell biocatalysts, applied in toxicity microscreening devices and also as efficient adsorbents of different types of organic and inorganic xenobiotics.^1–3 

Various nanoparticles have been used to modify cells surfaces, such as gold, silver, palladium or silica ones, carbon nanotubes, etc.¹  However, modification of cells with magnetic nano- and microparticles is exceptionally important and magnetically modified cells have been used in many applications. This review chapter focuses on the description of various procedures and materials to prepare magnetically responsive prokaryotic and eukaryotic cells and shows the most important examples of their applications.