Macroscopic and microscopic survey of enchondral ossification process in chicken embryo

Studying skeletal system in embryonic and after birth periods has been focused by researchers from different fields, biologists, embryologists and archaeologists, for a long time. This study can be useful in normal embryology and fatal disorders researches, as well as skeleton development system. This research may lead to experimental teratological studies. This paper studies enchondral ossification. in chicken embryo's long bone as a laboratory model by microscopic and macroscopic methods, which later analyzed by Alizarin red Alican blue double staining method. Results showed that, unlike mammals, birds' cartilage change to bone in four continuous stages including: resting phase, proliferative, hypertrophy and ossification phase. The difference is that there is no calcification phase in birds. Studying the samples prepared by Alizarin – Alican method shows that cartilage bone matrix become blue and red .respectively. We demonstrated that there is a gap between cartilage and bone which remains without color. This gap is hypertrophic phase that was confirmed by microscopic method.