Porous ion-exchanged fine cellulose particles, method for production thereof, and affinity carrier

An affinity carrier comprising porous fine cellulose particles, said cellulose particles being characterized by

• (a) comprising spherical or long spherical particles having a particle diameter of from 3 to 400 micrometers when wet,
• (b) comprising a crystalline cellulose phase and an amorphous crystalline phase,
• (c) having a crystallinity, determined by X-ray diffractometry, of 5 to 45%,
• (d) in a relation between pore diameter and pore volume of particles subjected to critical drying, which is measured by a mercury porosimeter method, said cellulose particles having a maximum value of pore volume within a pore diameter range of 0.006 to 1 micrometer, and the total volume of pores within the above range is 0.1 to 3 ml/g,
• (e) the amount of albumin that can be introduced into the cellulose particles is 30-330 mg/g, and
• (f) having a pressure resistance in the wet state of 5 to 83 kg/cm.sup.2.