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Identification of animal hair by mass spectrometry
Humpoláková, Karin ; Kučková, Štěpánka (advisor) ; Kolář, Karel (referee)
The goal of this bachelor work was to find out if it is possible to recognize mammal species by analyzing the proteins extracted from their hairs. This information could be of use, for example, in forensic science as evidence in cases of exotic animal species smuggling or it could be helpful for solving some specific criminal cases. Fur is a characteristic sign of mammals which is forming their body surface. It mainly consists of keratin, which is a fibrous protein. This bachelor thesis deals with proteomic analysis of animal hair using mass spectrometry working on MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization - Time of Flight) principle. Analyzed animal hairs were collected from ten local domestic and wild animals, such as dog, goat, cat, fallow deer, sika deer, degu, horse, rabbit, roe deer and Belgian blue calf breed. For the analyses of samples that are rich in proteins a specific enzyme cleavage by trypsin was used. The proteins were cleaved into peptides, from which mass spectra were obtained by MALDI-TOF mass spectrometry. Then these spectra were evaluated by the Principal Component Analysis (PCA) method. Then the obtained aminoacid sequences of the keratins found in the individual animal hair were searched through publicly available protein database - UniProt. The aminoacid...
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Determination of meat origin by mass spectrometry
Horníková, Marcela ; Kučková, Štěpánka (advisor) ; Chroustová, Kateřina (referee)
This thesis focuses on determination of meat origins based on mass spectrometry MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) followed by principal components analysis (PCA). Today, this method is mainly used for microbiological purposes and not used often for verification of food authenticity. Although the technique is very fast and suitable for analysis of suspicious products, the investment costs are high which probably leads to the fact that the technique remain not well known in the food industry. Eleven types of raw meat (fallow deer, beef, duck, goat, rabbit, chicken, coypu, fish, roe, pork and hare) were prepared as samples and dried out. All types of meat came from home-grown free-range animals or animals that were hunted in the wild. Proteins within the listed meats were enzymatically cleaved by trypsin. All mass spectra obtained by mass spectrometry were extracted and evaluated in computer program R. Same program was used for generating graphs (e.g. 3-D graph, cumulative graph and graph of variability). Based on these results it was decided if it is possible to differentiate between different types of meat. At first, all the samples were compared between each other and then were separated into two smaller groups and compared again. The samples that were not...
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