Ovalbumin blocking improves sensitivity and specificity of immunoglobulin M immunoblotting for serodiagnosis of patients with erythema migrans.

To improve the serodiagnosis of erythema migrans, we evaluated how sensitivity and specificity of immunoblotting are influenced by antigen concentration and blocking conditions. We found that an antigen concentration of 0.5 micrograms per lane in concert with ovalbumin blocking of the nitrocellulose provided the best results. In this case, 81% of the erythema migrans had positive immunoglobulin M tests, whereas only 33% were positive in a flagellum enzyme-linked immunosorbent assay (ELISA) and 28% were positive in a sonicate ELISA.