Detection of Brucella antibodies in eluted dried blood: a validation study.

In order to develop a rapid method for the diagnosis of human brucellosis, results of the ELISA test performed on dried whole blood spotted on filter paper were compared with those of the same test carried out on the serum of the same 160 subjects. Four patterns of elution were tested, combining incubation at 4 degrees C with different exposure times in an ultrasound bath. The best correlation (r = 0.79) for the IgG test, was obtained by using a 12-h incubation period plus a 20-min ultrasonic exposure; the same incubation period without ultrasound produced the best correlation for the IgM test (r = 0.81).