Protein Fingerprints: A New Forensic Tool

In the world of forensics, DNA has long been the star player. But what if there's more to a crime scene trace than just DNA? Enter proteomics, a field that studies proteins, the building blocks of life. While DNA tells us who, proteins can often tell us what. For example, they can reveal the type of body fluid found at a crime scene, like blood, saliva, or semen. Current methods for detecting these fluids have their downsides. Some tests can give false positives, and they usually only check for one fluid at a time. This can be a problem if the sample is a mix of different fluids, as it might need several tests, using up precious evidence.That's where this new method comes in. It uses mass spectrometry to find specific protein pieces, called peptides, that act like fingerprints for different body fluids. The best part? These proteins are left over after DNA is extracted from a sample. So, instead of throwing away this 'waste, ' scientists can now use it to gather more clues. The process involves a few steps: first, proteins are extracted and purified, then they're broken down into peptides using an enzyme called trypsin. Finally, these peptides are analyzed using a machine called a mass spectrometer. Early results show promise, with a list of potential protein and peptide markers for blood, saliva, and semen. This method could revolutionize forensic labs by allowing them to check for multiple body fluids at once, all from the leftovers of DNA profiling.