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Determination of the Physical Characteristics of an Individual From Biological Stains

NCJ Number
Date Published
January 2007
193 pages
This study examined whether the determination of an individual’s age from dried physiological stains is feasible.
The study was unable to find a correlation between telomere length and age in dried bloodstains, using a variety of analytical approaches. There were some conditions, however, under which the age of the blood donor could be detected from bloodstains. A series of specificity performance checks carried out on the qRT-PCR assays revealed that the HBG(1/2)n transcripts appear to be restricted to blood from newborns in the human (or at least primate) lineage. The assays appear to be sufficiently sensitive and robust for forensic use, in that only a few cell equivalents of total RNA are required. The newborn blood-specific transcripts were detectable at least up to 15 months in the dried state. A triplex real-time PCR assay has been designed and developed for two other age-specific biomarkers (COL1A2 and IGFBP3) that also includes the housekeeping gene S15. The conditions of the assay are such that the relative expression of these three transcripts differs in an age-dependent manner. Consequently, the triplex qRT-PCR assay can be used to categorize blood stain donors as likely originating from an individual belonging to one of four different age classes: 1 hour-3 months, 4 months-4 years, 5-18 years, and older than 18 years old. The triplex apparently has a high level of species specificity, being confined to primates. The assay can be used to predict the blood stain donor’s age in stains left at room temperature for up to 18 months. This effort to attach an age range for the donors of blood stains is particularly useful in narrowing suspects when a DNA profile obtained from a stain cannot be matched to any existing suspect or any profiles in DNA databases. 39 figures, 19 tables, 108 references, and appended supplementary information on candidate genes

Date Published: January 1, 2007