Abstract: Uniform discoid particles made of at least one member selected from the group consisting of a natural high molecular substance, a synthetic high molecular substance and an inorganic compound, wherein each particle has a diameter of 20 to 2,000 .mu.m and a thickness/diameter ratio of 1/2 to 1/50, and not less than 80% of the whole particles have a diameter within the range of 0.5 to 2 times the number average diameter, and a process for preparing the particles. The discoid particle of the present invention has a larger surface area and therefore has a high efficiency when employed in various uses such as a parent material for an ion exchange resin, a packing material for a chromatograph, a catalyst and an culture medium for cell culture in comparison with conventional spherical particle.

Abstract: Uniform polymer particles in a spherical form, having a three dimensional network structure, wherein not less than 80% by volume of the whole particles have a particle size within the range of .+-.20% of the volume average particle size of said uniform polymer particles, and said uniform polymer particles do not include particles having a particle size of not more than 5% of the volume average particle size, a process for preparing the uniform polymer particles, an apparatus suitable for use in the process, and a method of direct extracorporeal hemo-perfusion treatment using the uniform polymer particles. The uniform polymer particles of the present invention can be also used in various uses such as a parent material for an ion exchange resin, an adsorbent, and a packing material for a chromatography.