a method of carrying out a solid phase chemical reaction or a filtration step to remove a solid from a liquid utilizing ferromagnetic particles . the particles may have a porous or otherwise bondable solid support material having adsorbed or chemically bonded thereon a biologically active substance to make them biologically active . alternatively , the particles may act as an inert medium to convey a solid precipitate out of a liquid . the process involves the addition of the ferromagnetic particles to a potentially reactive fluid . after the fluid has reacted either as a result of contact with the biologically active material or by a process causing a precipitate in the fluid , the particles may be separated from the fluid by bringing the particles into close proximity with a magnet such as an electromagnet . when sufficient particles are held in an elongated container and a magnetic force is exerted to hold the particles in a porous mass across the container , the particles may be moved through the liquid to filter solid particles from the liquid . a second container may be placed over a portion of the elongated container on the particles and any entrapped precipitate may be removed from the elongated container . the particles may alternatively have a bondable surface capable of adsorption or chemical coupling of biologically active materials . polymer and ceramic biomaterial supports and particular combinations with ferromagnetic materials are disclosed . a valve formed from the ferromagnetic particles is also disclosed herein .