What is Forensic science?
Forensic science is a huge field comprising very different research and application areas, such as DNA profiling, anthropology, entomology and pathology, but also computer science or fire investigation. During criminal investigation, which is executed after violation of criminal and civil laws, different forensic mapping solutions are applied. Thus, forensic scientists collect, preserve, and analyze scientific pieces of evidence, such as fingerprints, fibers, hair and skin flakes or computer data which are then evaluated to solve a criminal case.
What are the challenges in forensics?
The key to forensic science is to get as much information as possible from the samples available. The major challenges in forensic science, however, are the sample amount and sample quality. The forensic scientist is routinely faced with working with small samples or complex mixtures and there is no opportunity to get a second sample. Thus, they must be able to isolate the cells of interest effectively and generate a full audit trail of the work they have done.
Minute sample volumes are demanding professional forensics solutions. Only very few kits and protocols for DNA purification and amplification have been optimized for small amount of sample. Intriguingly, downscaling is not always applicable as many factors have to be considered. For example, loss of material to surfaces such as reaction tubes and columns due to unspecific adhesion is much more pronounced with low sample volumes and low sample concentrations. Special materials and coatings can help to minimize these effects thus providing special solutions for forensics.
In addition to low sample amounts, forensic scientists also have to cope with samples of low quality. Immediately after the crime case had taken place, traces and samples starts to degrade. Therefore, also optimized diagnostic forensic solutions need to be developed.
How can MMI help in forensics?
In the modern crime lab, all samples are screened with the aim of isolating DNA traces left behind by the perpetrator. MMI provides unique technologies to isolate and separate cells selectively under full video control. Forensic tapes, for example are being applied and analyzed for skin flakes to identify the DNA profile of the potential offender. To be able to separate the single cells from each other, MMI offers the MMI CellCut laser microdissection system. With its high-power laser option, even thicker materials such as forensic tapes can be efficiently cut.
Both, the MMI CellEctor and the MMI CellCut, can also be applied to isolate single cells from blood samples or swabs, such as vaginal swabs after rape which typically contain sperm cells from the offender. It may be difficult to get good quality DNA profiles from the sperm cells due to them being masked by the high concentration of the victim’s DNA present on the swabs. The MMI CellCut is the only commercially available laser microdissection system that allows the location, cutting and isolation of sperm cells under fully audited visual control and including full documentation. The programmable isolation cap allows collection of as many as 300 sperm cells on a single cap, thus maximizing the chances to obtain a high quality full DNA profile that can be searched on available databases. In addition, in rare cases with more than one rapists, it is essential to separately analyze sperm cells to not obtain a mixed DNA profile but a meaningful DNA profile of each offender.
Furthermore, the MMI CellCut can also be utilized for the isolation of cells from archived slides making it a powerful tool in the investigation of old unsolved cases.
MMI instruments are approved to be an essential forensic technology solution in the fight against crime. They are robust, reliable, user friendly and provide results quickly for downstream DNA analyses. In addition, all MMI systems can be individually combined and integrated on a single microscope platform. Contact us to configure your tool for forensic science.