Acoustic Differential Extraction - ultrasonic DNA-extraction from sexual assault evidence
Author
Editor
- Ewald Benes
Summary, in English
Isolation of the male and female DNA is one of the most important steps in obtaining the DNA profile of the perpetrator in sexual assault cases. The sample is obtained by taking a vaginal swab containing both epithelial cells from the female and sperm cells from the male from the victim. The purity of the extracted male fraction decides whether or not a single-source DNA profile of the suspect will be obtained or not. The existing techniques are have poor separation efficiency, time-consuming, labour-intensive and are neither easily automated nor integrated with further analysis steps.
A novel method of DNA extraction based on ultrasonic trapping, Acoustic Differential Extraction, has been developed. A microfluidic device using laminar flow valving and miniature PZT transducers retains the sperm cells while mobilizing the female fraction into a separate outlet. The device was evaluated using a mock sexual assault sample and the separated fractions were analyzed using quantitative PCR and STR-profiling.
A 16-fold enrichment of the male fraction, making an originally hard-to-detect-male DNA profile readily profiled, has been demonstrated. The STR-profiling of the male and female fractions showed a male fraction purity of up to 99 % making it possible to obtain a single-source DNA-profile of the suspect. The microfluidic format of the device makes it possible to downscale the sample time from 4-8 hours to 10 minutes. It is also possible to integrate this method with further downstream analysis steps necessarey for the full forensic DNA analysis.
A novel method of DNA extraction based on ultrasonic trapping, Acoustic Differential Extraction, has been developed. A microfluidic device using laminar flow valving and miniature PZT transducers retains the sperm cells while mobilizing the female fraction into a separate outlet. The device was evaluated using a mock sexual assault sample and the separated fractions were analyzed using quantitative PCR and STR-profiling.
A 16-fold enrichment of the male fraction, making an originally hard-to-detect-male DNA profile readily profiled, has been demonstrated. The STR-profiling of the male and female fractions showed a male fraction purity of up to 99 % making it possible to obtain a single-source DNA-profile of the suspect. The microfluidic format of the device makes it possible to downscale the sample time from 4-8 hours to 10 minutes. It is also possible to integrate this method with further downstream analysis steps necessarey for the full forensic DNA analysis.
Department/s
Publishing year
2007
Language
English
Pages
151-151
Publication/Series
International Congress on Ultrasonics
Volume
1
Document type
Conference paper
Publisher
International Congress on Ultrasonics
Topic
- Medical Engineering
Conference name
International Congress on Ultrasonics 2007
Conference date
2007-04-09
Status
Published