[Age estimation using content of sjTREC in human peripheral blood].

Objective: To determine and verify the correlation formula of age estimation using the content of signal joint T-cell receptor excision DNA circle (sjTREC) in human peripheral blood and to discuss its application value in forensic biological practice.

Methods: The samples of peripheral blood stains were collected from 30 healthy unrelated individuals whose ages were known. The DNAs were extracted from the samples stored at room temperature after 4 weeks. The content of sjTREC was measured by real-time fluorescent quantitative PCR technique, and the TATA box binding protein (TBP) was selected as reference genes. The age of each sample was predicted with the formula which was Age = -7.181 5 Y-42.458 +/- 9.42 (Y = dCtTBP-sjTREC), and the result was compared with the real age of each individual to determine the accuracy of the formula.

Results: sjTREC and TBP gene were detectable in all 30 samples of peripheral blood. The contents of sjTREC in human peripheral blood showed a decreasing tendency with aging. The accuracy rate for the age estimation by this method was 76.67%.

Conclusion: The method for the age estimation with the content of sjTREC was simple, fast, sensitive, and good species specific with important potential application prospect.