Extraction and partial characterization of surfactant-soluble antigens from adult female Dirofilaria immitis.

Antigens were solubilized from aqueous-insoluble material of adult female Dirofilaria immitis with Triton X-100 and sodium dodecyl sulfate (SDS) and partially characterized. Concentrations of 2.1-8.3 mg Triton X-100/mg total protein and 1.06-4.26 mg SDS/mg total protein were used to solubilize antigens. Triton X-100 was more efficient in solubilizing protein than SDS; Triton X-100 and SDS released 75% and 26% of the available protein, respectively. Protein mixtures solubilized with different levels of Triton X-100 appeared to be identical in immunodiffusion. Crossed immunoelectrophoresis revealed six antigen systems. Triton X-100 solubilized antigens did not react in immunodiffusion with sera from 7 D. immitis-infected, microfilaremic dogs, but did react with sera from 4 of 5 dogs with occult D. immitis infections.