Patent ID: 8268569

Claim:
A method of using a recombinant 15-kDa polypeptide in an immunoassay to detect an infection of Bartonella henselae in a mammal, comprising the steps of: (a) expressing a recombinant 15-kDa polypeptide having an amino acid sequence of SEQ ID NO. 2 in an E. coli cell, said expressing step comprises: (i) introducing a 15-kDa insert DNA having a nucleotide sequence of SEQ ID NO. 1 in said E. coli cell; (ii) growing said E. coli cell that has said 15-kDa insert DNA; (iii) adding 5-10 mg/mL glucose followed by IPTG; and (iv) isolating said recombinant 15-kDa polypeptide, (b) immobilizing said recombinant 15-kDa polypeptide onto a surface; (c) contacting said immobilized recombinant 15-kDa polypeptide with a biological sample obtained from a mammal, said mammal is suspected of an infection of Bartonella henselae , under conditions that allow formation of an antibody-antigen complex; and (d) detecting the formation of said antibody-antigen complex, wherein said detected antibody-antigen complex is indicative of the presence of said antibody against Bartonella henselae in said biological sample, and is indicative of an infection of Bartonella henselae in said mammal.