A cosmid clone containing the uteroferrin gene (ACP5) was selected from a cosmid library of swine genomic fragments by colony hybridization using uteroferrin cDNA as a probe. The genomic fragment thus cloned was examined by Southern blot and sequence analysis which demonstrated that it contained at least a part of the uteroferrin gene. The cosmid clone DNA was labeled with biotin, and used as a probe for in situ hybridization to swine chromosomes. Hybridization was visualized by the FITC-labeled streptavidin/biotinylated anti-streptavidin system together with R-banding of chromosomes. The hybridization signals revealed that the uteroferrin gene (ACP5) is located on swine chromosome 2q12→q2