<；P>；PROBLEM TO BE SOLVED: To solve the problems of known immobilized erythrocyte obtained by fixing a suspension of avian erythrocyte with 10% formalin solution and still keeping the binding capability to an erythrocyte agglutinin of virus, comprising the lowering of the virus binding capability caused by the loss of the function of a part of receptor binding to erythrocyte agglutinin or the necessity in the preparation in use because the erythrocyte is unable to store over a long period while keeping the receptor function. <；P>；SOLUTION: A stable immobilized avian erythrocyte is produced by carrying out (a) a step to perform bubbling treatment of a suspension of avian, guinea pig or human O-type erythrocyte optionally with carbon monoxide and (b) a step to treat the obtained suspension of deep red erythrocyte with a formalin solution in the presence of a monosaccharide or disaccharide. A freeze-dried product containing a monosaccharide or a disaccharide gives immobilized erythrocyte keeping high virus binding property which is stable over a period as long as &ge；5 years. A mask extremely useful for the prevention of influenza virus can be produced by supporting the stabilized erythrocyte to a filter of a mask, etc. <；P>；COPYRIGHT: (C)2008,JPO&INPIT
