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Updated: Apr 30, 2026
Filtration Isolation of Nucleic Acids: A Simple and Rapid DNA Extraction Method
Published on: August 6, 2016
DNA extraction from filter-paper spots of vaginal samples collected after sexual violence
Elisabete A Campos1, Denise R Pitta1, Fernanda A Costa1
1Specialized Clinical Laboratory, Center for Women's Integrated Healthcare, School of Medical Sciences, University of Campinas, Campinas, Brazil.
Objective:
To detect the presence of male DNA in vaginal samples collected from survivors of sexual violence and stored on filter paper.
Methods:
A pilot study was conducted to evaluate 10 vaginal samples spotted on sterile filter paper: 6 collected at random in April 2009 and 4 in October 2010. Time between sexual assault and sample collection was 4-48hours. After drying at room temperature, the samples were placed in a sterile envelope and stored for 2-3years until processing. DNA extraction was confirmed by polymerase chain reaction for human β-globin, and the presence of prostate-specific antigen (PSA) was quantified. The presence of the Y chromosome was detected using primers for sequences in the TSPY (Y7/Y8 and DYS14) and SRY genes.
Results:
β-Globin was detected in all 10 samples, while 2 samples were positive for PSA. Half of the samples amplified the Y7/Y8 and DYS14 sequences of the TSPY gene and 30% amplified the SRY gene sequence of the Y chromosome. Four male samples and 1 female sample served as controls.
Conclusion:
Filter-paper spots stored for periods of up to 3years proved adequate for preserving genetic material from vaginal samples collected following sexual violence.
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