Patent ID: 8460638

Claim:
A method of fluorescence imaging a mammal comprising: administering to the mammal an effective amount of a non-labeled fluorescent microsphere comprising a primary amine polymer, wherein the microsphere does not contain an additional fluorescent substance, and wherein at least one primary amine group in the primary amine polymer has the structure of —N═R—, in which R is a residue after the reaction of an aldehyde-type cross-linking substance, and the other primary amine groups have the structure of —NH 2 ; and imaging fluorescence from said microspheres; and wherein the non-labeled fluorescent microsphere is produced according to a method, comprising: mixing a solution of the primary amine polymer with an oil phase to make a W/O type emulsion; adding a cross-linking agent into the W/O type emulsion to perform a cross-linking reaction so as to obtain solidified microspheres; and subjecting the solidified microspheres to centrifugation washing and collection, and obtaining the non-labeled fluorescent microspheres after drying, wherein the cross-linking agent is an aldehyde-type cross-linking substance and the primary amine polymer is chitosan or polylysine.