immobilization of enzymes is carried out by covering the surface of a solid support with an enzyme and then contacting the enzyme with an immobilizing reagent in the vapor phase . the immobilizing reagent is preferably an aldehyde or a polymerized aldehyde . by having the immobilizing reagent in vapor phase , the immobilizing reagent concentration can be easily controlled by the vapor pressure . additionally , there is obtained a uniform covering of immobilized enzyme on the support , and support surfaces which are uneven or curved can be covered with immobilized enzyme regardless of size .