Law enforcement agencies use DNA testing to determine whether or not some piece of biological matter – like a hair follicle or fingernail – at a crime scene matches that of a person of interest. Various methods are used to analyze the evidence, and sometimes results come back with a match, linking an individual to a crime; other times, they can show that the suspected person did not commit an alleged offense, and exonerate them.
Although DNA testing can be instrumental in eliminating suspects and solving cases, biological matter is a very delicate type of evidence. If not enough was collected or it was mishandled, technicians might not be able to test it, or results could come back inconclusive.
The Proteomics Technique
Seeking new ways to test biological evidence, researchers at the University of California, Davis have been fine-tuning a method called proteomics. This technique uses reverse engineering to identify the DNA sequence in a piece of evidence.
Typically, when a crime lab tests the biological matter, they will separate the DNA from a cell and use a special technique to determine the length of the DNA chain sequence. However, when the sample isn’t adequate, the process might not work correctly.
Working from Protein to DNA
With proteomics, analysts could use proteins to determine a DNA sequence. A person’s DNA sends messages throughout the body to produce proteins (the information sent allows the person to develop and survive). DNA serves as a set of instructions that enzymes translate into messenger ribonucleic acid (mRNA). The mRNA is then turned into a language that amino acids understand. The order of the amino acid language allows the body to produce specific proteins for particular tasks.
If the DNA sequence is known, the amino acid sequence is also known, and, therefore, the protein can be identified. The proteomics technique works backwords. The researchers said that if you know the protein, you can figure out the amino acid sequence and then the DNA.
Analyzing Small and Older Biological Matter Samples
Using proteomics methods in a crime lab would allow analysts to determine a person’s DNA even if the sample wasn’t large enough to conduct traditional DNA testing. The new process can work using only 50 nanograms of protein. That’s about the amount found in half an inch of human hair.
The researchers said that in their tests, they were able to conduct the proteomic method with hair, which doesn’t contain much DNA, from various parts of the human body. They also noted that things such as dyes, greying, and peroxide treatments did not hinder their ability to identify the proteins.
Although still needing further testing and refinement, the proteomic tool would have profound implications for criminal investigations, such as sexual assault or murder cases. In situations where collected evidence was too small for traditional testing or the sample was old or degraded, analysts could turn to a protein analysis to uncover the DNA sequence.
The UC Davis researchers believe that the method could be ready for public use in as little as one year.
The Law Office of Rene A. Flores PLLC: Protecting Your Rights
Our attorney is a forensic lawyer-scientist and knows how crime labs use various testing methods to analyze evidence. We understand that samples could become degraded, and traditional DNA testing results might not be conclusive. If you were charged with an offense in Hidalgo County, we will provide zealous representation. We will thoroughly examine your case and challenge chemical-based evidence that may not be reliable.
We are ready to work toward getting your charges reduced or dropped. Schedule your free consultation today by calling us at (956) 606-3606 or contacting us online.