With respect to dating of a bone, a bone more than 100 years old contain:

Dating of skeletal remains 1.Nitrogen content <50 years old:4-5 g%, 50-100 years old: 3.5g% 2.Amino acids: Total: 15 AA (glycine & alanine Predominant) > 50 years: Hydroxyproline and proline disappear. > 100 years old: 7AA 3.Blood pigment tests positive for upto 100 years. 4.UV fluorescence: Fresh bone will fluoresce across the whole surface from periosteum to marrow cavity. As time lengthens, the fluorescent zone narrows, breaks up. 5.Estimation of radioactive carbon (C-14):There is no significant fall of C-14 during the first century after death.