Figure 4. Western blot and cross-adsorption results in a patient with Bartonella quintana endocarditis. A) Nonadsorbed. B) Adsorbed with B. quintana. C) Adsorbed with B. henselae. Lane 1, B. quintana; lane 2, B. henselae; lane 3, B. elizabethae; lane 4, B. vinsonii subsp. Berkhoffi; lane 5, B. vinsonii subsp. Arupensis. Before adsorption (A), antibodies are detected against all species (1, 2, 3, 4, and 5). After adsorption with B. quintana antigen (B), all antibodies disappear. After adsorption with B. henselae antigen (C), antibodies against B. quintana (1) persist. This reaction shows B. quintana infection.