Use of whole blood lymphocyte stimulation test for immunocompetency studies in bald eagles, red-tailed hawks, and great horned owls.

: Mitogen-induced whole blood lymphocyte stimulation tests for immunocompetency studies in bald eagles (Haliaeetus leucocephalus), red-tailed hawks (Buteo jamaicensis), and great horned owls (Bubo virginianus) were developed. Combinations of incubation times, blood dilutions, concentrations of [3H]thymidine and [125I]2-deoxyuridine, antibiotics, phytohemagglutinin-P, and concanavalin A were tested for their effects on the stimulation index (SI). An antibiotic combination of gentamicin plus amphotericin B yielded low SI with lymphocytes from bald eagles, but not with lymphocytes from great horned owls or red-tailed hawks. Penicillin plus streptomycin caused no such depression of SI. Lymphocytes from all 3 species yielded maximum responses with a 48-hour prelabel and 12- to- 16 hour postlabel incubation period at 41 C and 1:20 blood dilution. Optimal mitogen concentrations for lymphocytes from bald eagles, red-tailed hawks, and great horned owls were 25 micrograms, 10 micrograms, and 10 micrograms of phytohemagglutinin-P/well, respectively, and 2.5 micrograms, 10 micrograms, and 10 micrograms of concanavalin A/well, respectively. Differences in SI were not seen between the 2 radioactive labels. The optimal concentration of the [3H]thymidine label ranged from 0.06 to 0.125 microCi/well.