A brush-type polymeric interface was prepared by grafting glycidyl methacrylate (GMA), an epoxy-group-containing vinyl monomer, onto a polyethylene (PE)-based backbone using the radiation-induced graft polymerization (RIGP) technique. PE was irradiated with an electron beam at a total dose ranging from 10 to 200 kGy before grafting. GMA was grafted and its epoxy ring was opened by diethylamine (DEA) to introduce tertiary amino groups. By irradiating PE before grafting at various total doses, the density of the graft chain was altered, and by controlling the degree of GMA grafting, the length of the graft chain was changed. As a result, a strategy for tailoring the characteristics of a "brush bed" on the polymeric interface to make it desirable for capturing microbial cells has been explored. The prepared brush-type interfaces were examined for their microbial-cell-capturing ability by contacting with a Staphylococcus aureus IFO 12732 cell suspension in batch mode. The capturing-rate constant of each interface is determined and used as a parameter for evaluation. The brush-type interface prepared at a high total dose with a high degree of GMA grafting was found to act as a fast-capturing interface for S. aureus.