Application of flow focusing to the break-up of a magnetite suspension jet for the production of paramagnetic microparticles

Abstract

Paramagnetic particles offer an extensive improvement in the magnetic separation or purification of a wide variety of protein molecules. Most commercial paramagnetic particles are synthesized by laborious and costly procedures. A straightforward production of paramagnetic microparticles with homogeneous and selectable sizes using flow focusing (FF) technology is described in this work. The development of an initial formulation of a stable iron oxide suspension compatible with the FF requirements is also reported. The obtained particles, below 10 microns in diameter and presenting smooth and reactive surface, were codified with an organic fluorophore and showed excellent properties for covalent attachment of biomolecules such as proteins and its subsequent recognition by flow cytometry. Furthermore, particles with suitable magnetite content resulted as well-suited for commercial magnet separators for these purposes.