Fig. 1

Model of in ovo delivery and penetration of the bioactive solution through the chorioallantoic membrane into the circulatory system of the chicken embryo. For in ovo injection, 0.2 ml of a blue dye (E132, indigotine, artificial dye used for food coloring) at a concentration of 0.01 g/ml was injected in ovo on day 12 of egg incubation. Blue dye was deposited into the air cell. The eggs were sealed and incubation was continued until 19 of egg incubation. Penetration of the dye through chorioallantoic membrane was observed daily by dissecting permeable outer shell membrane from semi-permeable inner cell membrane. After 3 days (i.e., from 15 of egg incubation onwards) the dye was transferred to the blood vessel on the inner shell membrane. The stained vessel is marked with an arrow Steady influx of the dye through the chorioallantoic membrane was observed until 19 of egg incubation, when the experiment was terminated