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Evaluation of Aspartic Acid Racemization Ratios in the Human Femur for Age Estimation

NCJ Number
175972
Journal
Journal of Forensic Sciences Volume: 43 Issue: 5 Dated: September 1998 Pages: 949-953
Author(s)
S Ohtani; Y Matsushima; Y Kobayashi; K Kishi
Date Published
1998
Length
5 pages
Annotation
This paper reports on the evaluation of levels of D-aspartic acid (D/L ratio) in cranial non-collagen proteins (acid-soluble peptide fractions) as a means of estimating the age of a body at the time of death, since these levels of D-aspartic acid have been reported to increase with age.
Abstract
The experiment isolated total amino acid fractions from the femur and separately isolated acid-insoluble collagen fraction and acid-soluble peptide fractions; then D/L ratios were measured from each fraction by gas chromatography. Researchers evaluated the applicability of the fractions' D/L ratios for age estimation based on the fraction correlation coefficient. A gender-related difference was observed in the D/L ratio. In particular, aged females showed a low ratio, suggesting an association with bone disorders. In males, the D/L ratios of acid-soluble peptide fraction showed the highest correlation rate (r = 0.969) with age, and those of total amino acid fraction showed the highest correlation rate (r = 0.633) with age in females. Without separation of male and female, the D/L ratios of total amino acid fraction showed the highest value (r = 0.853). The D/L ratio of acid-soluble peptide fractions differed according to the size of bone powder particles, being higher for larger particle sizes. These results suggest that the application of D/L ratio from total amino acid fraction is the most effective method for estimating age from the human femur; however, care is necessary when studying cadavers that might be females. 1 table, 3 figures, and 22 references