title: Mass spectrometry-based proteomics as a tool to identify biological matrices in forensic science.
abstract: In forensic casework analysis, identification of the biological matrix and the species of a forensic trace, preferably without loss of DNA, is of major importance. The biological matrices that can be encountered in a forensic context are blood (human or non-human), saliva, semen, vaginal fluid, and to a lesser extent nasal secretions, feces, and urine. All these matrices were applied on swabs and digested with trypsin in order to obtain peptides. These peptides were injected on a mass spectrometer (ESI Q-TOF) resulting in the detection of several biomarkers that were used to build a decision tree for matrix identification. Saliva and blood were characterized by the presence of alpha-amylase 1 and hemoglobin, respectively. In vaginal fluid, cornulin, cornifin, and/or involucrin were found as biomarkers while semenogelin, prostate-specific antigen, and/or acid phosphatase were characteristic proteins for semen. Uromodulin or AMBP protein imply the presence of urine, while plunc protein is present in nasal secretions. Feces could be determined by the presence of immunoglobulins without hemoglobin. The biomarkers for the most frequently encountered biological matrices (saliva, blood, vaginal fluid, and semen) were validated in blind experiments and on real forensic samples. Additionally, by means of this proteomic approach, species identification was possible. This approach has the advantage that the analysis is performed on the first "washing" step of the chelex DNA extraction, a solution which is normally discarded, and that one single test is sufficient to determine the identity and the species of the biological matrix, while the conventional methods require cascade testing. This technique can be considered as a useful additional tool for biological matrix identification in forensic science and holds the promise of further automation.
authors: Laboratory for Pharmaceutical Biotechnology, Ghent University, Harelbekestraat 72, 9000, Ghent, Belgium.
authors: Katleen
authors: K
authors: Van Steendam
authors: Marlies
authors: M
authors: De Ceuleneer
authors: Maarten
authors: M
authors: Dhaenens
authors: David
authors: D
authors: Van Hoofstat
authors: Dieter
authors: D
authors: Deforce
mesh_terms: D000135:Acid Phosphatase; D000818:Animals; D015415:Biomarkers / Q000032:analysis; D001774:Blood Chemical Analysis; D002417:Cattle; D002582:Cervix Mucus / Q000737:chemistry; D055233:Cornified Envelope Proline-Rich Proteins / Q000032:analysis; D003663:Decision Trees; D004285:Dogs; D005243:Feces / Q000737:chemistry; D005260:Female; D049429:Forensic Pathology; D055554:Hemoglobin Subunits / Q000032:analysis; D006801:Humans; D008297:Male; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000032:analysis; D009297:Nasal Mucosa / Q000737:chemistry; D009363:Neoplasm Proteins / Q000032:analysis; D017430:Prostate-Specific Antigen / Q000032:analysis; D011498:Protein Precursors / Q000032:analysis; D017027:Protein Tyrosine Phosphatases / Q000032:analysis; D040901:Proteomics; D012463:Saliva / Q000737:chemistry; D012661:Semen / Q000737:chemistry; D029607:Seminal Vesicle Secretory Proteins / Q000032:analysis; D014556:Urine / Q000737:chemistry; D000516:alpha-Amylases / Q000032:analysis
chemical_list: D015415:Biomarkers; C418764:CRNN protein, human; D055233:Cornified Envelope Proline-Rich Proteins; D055554:Hemoglobin Subunits; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D011498:Protein Precursors; D029607:Seminal Vesicle Secretory Proteins; C424482:seminal vesicle-specific antigen; C032253:involucrin; D000135:Acid Phosphatase; C428439:prostatic acid phosphatase; D017027:Protein Tyrosine Phosphatases; D000516:alpha-Amylases; D017430:Prostate-Specific Antigen