By Shriya Chourasia | 28th April 2023
Unlocking the truth: How magnetic bead silica-based technology is changing the game in DNA Forensics?
Forensic science is playing a pivotal role in solving crimes and administering justice. One of the most critical components of forensics is DNA testing which provides valuable information about the identities of suspect and victims.
The process of DNA extraction is crucial step in forensic analysis and the recent advancement of magnetic bead silica technology has significantly improved this process. Magnetic bead silica-based DNA extraction is a method used to extract DNA from various biological samples using magnetic bead coated with silica.
Basic Principle and Working
The basic principle of working of silica-based DNA extraction is binding of DNA to silica particles in the presence of chaotropic salts which disrupts the hydrogen bonding between the nucleic acid bases and exposes negatively charged phosphate backbone.
The DNA lysate is then mixed with silica particles that are coated with the binding agent which is positively charged such as guanidine or ammonium ions. The binding agent interacts with the negatively charged phosphate groups of DNA, causing the DNA to bind to the silica particles while other cellular debris is removed through washing steps.
Once the DNA is bound to the silica particles, it can be eluted from the particles using a low-salt or high-pH buffer, which reverses the binding interaction between the DNA and the silica particles. The purified DNA can then be used for various downstream applications such as PCR, sequencing, or cloning.
Advantages
This process offers many advantages for forensic investigators, including faster and more efficient DNA extraction, higher yields of DNA, and reduced risk of contamination. Additionally, magnetic bead silica DNA extraction can be easily automated, which can save time and increase the throughput of forensic laboratories.
Another benefit is its high sensitivity, meaning that it can detect very small amounts of DNA in a sample. This can be particularly important in forensic investigations, where even trace amounts of DNA can be critical in identifying suspects or victims.
There are several companies that offer hi-tech instruments based on this principle such as Thermo Fisher Scientific offers a range of magnetic bead-based silica adsorption products, including Dynabeads MyOne. Silane Promega Corporation offers MagneSil products, which are silica-coated magnetic beads that can be used for DNA purification, RNA purification, and protein isolation.
Limitations
There are several limitations associated with this technique that researchers, forensic experts, and scientists should be aware of which includes its high cost, requirement of more sample size, DNA fragmentation, reduced DNA yields due to the presence of inhibitors and limited applicability as it may not be suitable for extracting DNA from certain sample types, such as those containing complex mixtures or heavily degraded DNA.
Future advancements in the process of magnetic bead silica-based DNA extraction
The continued development and optimization of the magnetic bead silica-based DNA extraction technique by integration of automation, optimization of bead industry, miniaturization, use of magnetic nanoparticles and integration of next generation sequencing technologies could enable faster and more accurate analysis of DNA, allowing for more comprehensive and detailed genetic information to be obtained. These advancements are likely to improve its efficiency, sensitivity, and applicability in a variety of research and forensic applications.
Conclusion
Magnetic bead silica DNA extraction technology has greatly improved the efficiency and accuracy of DNA analysis in forensic science. By providing fast, sensitive, and reliable results, this technology is helping to uncover the truth and bring justice to victims of crime. Its future advancements will also aid the criminal justice system and the research authorities to utilize it to its fullest potential.
Learn more about the technique:
- Wong, R.C., Hirst, C., Leung, W.T., et al. (2003). Validation and implementation of a DNA extraction system for forensic casework using magnetic microbeads. Forensic Science International, 133(1-2), 21-28.
- Zhang, L., Luo, H., Hao, S., et al. (2013). Comparison of five DNA extraction methods for forensic analysis with different sample types. Journal of Forensic Sciences, 58(S1), S146-S151.
- Mansour, S.A., Khair-Eldeen, M.A., Eldebaky, H.A., et al. (2017). Evaluation of magnetic bead extraction of DNA from bone and teeth for forensic DNA typing. Egyptian Journal of Forensic Sciences, 7(2), 69-74.
- Elkins, K.M., Chabot, A., and Vannier, M.W. (2017). Comparison of a magnetic bead-based DNA extraction method with a silica membrane-based method for forensic casework analysis. Journal of Forensic Sciences, 62(2), 301-307.
- Rahikainen, A.L., Palo, J.U., and Sajantila, A. (2009). Comparison of DNA extraction methods for casework samples. Forensic Science International: Genetics Supplement Series, 2(1), 515-517.