Sensitivity of chick embryo to various solvents used in egg injection studies.

Two experiments were conducted to study the sensitivity of developing chicken embryos to various solvents used as vehicles and their effect on hatchability. No significant differences on embryonic mortality were observed between the sham-injected control and corn oil-injected groups. Acetone, ethylene glycol, and ethanol (0.10 ml/egg) significantly reduced the percentage hatchability and showed a high embryonic mortality during the first week of incubation. Levels of cottonseed oil (0.05-0.10 ml) and propylene glycol (0.05-0.15 ml) were well tolerated by the developing embryo but were slightly inferior to corn oil. Levels of 0.05-0.15 ml of corn oil are suitable vehicles for fat soluble compounds in studies involving the injection of eggs. Higher levels of solvent can be injected at later incubation periods. The choice of the best solvent must be made depending upon (1) solubility of test material, (2) amount of test material needed, (3) toxicity of the solvent at the appropriate levels, (4) route of administration, and (5) stage of development.