THE HEN EGG IN TOXICITY AND TERATOGENICITY STUDIES.

Abstract A number of test compounds has been administered to hen eggs, both by injection into the yolk sac and by diffusion through the shell. Applying the injection technique to small groups of eggs, it proved impossible to obtain regular dose-response effects, in either unincubated or 5-day incubated eggs. Using the immersion technique to introduce compounds by diffusion, no suitable non-toxic solvent could be found for use with the 5-day incubated egg. n -Propanol and water appeared to be suitable for experiments with the unincubated egg. With these solvents there was a direct relationship between the concentration of test compound in the solution and the incidence of abnormalities. No such clear-cut result was observed for the percentage hatch. It is concluded that unless large numbers of eggs are employed, neither method is reliable as an indicator of toxicity.