Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-25648 Zeitschriftenartikel Krause, Benjamin Christoph; Seifert, Stephan; Panne, Ulrich; Kneipp, Janina; Weidner, Steffen Matrix-assisted laser desorption/ionization mass spectrometric investigation of pollen and their classification by multivariate statistics RATIONALE A fast and reliable online identification of pollen is not yet available. The identification of pollen is based mainly on the evaluation of morphological data obtained by microscopic methods. METHODS Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) was applied to the analysis of extracts and milled pollen samples. The obtained MALDI data were explored for characteristic peak patterns which could be subjected to a multivariate statistical analysis. RESULTS Two sample preparation methods are presented, which require only minimal or no chemical extraction of the pollen. MALDI pollen spectra could be recorded showing various peak patterns. A multivariate statistics approach allowed the classification of pollen into clusters indicating similarities and differences between various species. CONCLUSIONS These results demonstrate the potential and the reliability of MALDI-TOF MS for the identification and, in combination with multivariate statistics, also for the classification of pollen. Chichester Wiley 2012 Rapid communications in mass spectrometry 26 9 1032 1038 10.1002/rcm.6202 2016-02-19 OPUS4-45607 Zeitschriftenartikel Lauer, Franziska; Diehn, Sabrina; Seifert, Stephan; Kneipp, Janina; Sauerland, V.; Barahona, C.; Weidner, Steffen Multivariate analysis of MALDI imaging mass spectrometry data of mixtures of single pollen grains Mixtures of pollen grains of three different species (Corylus avellana, Alnus cordata, and Pinus sylvestris) were investigated by matrixassisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF imaging MS). The amount of pollen grains was reduced stepwise from > 10 to single pollen grains. For sample pretreatment, we modified a previously applied approach, where any additional extraction steps were omitted. Our results show that characteristic pollen MALDI mass spectra can be obtained from a single pollen grain, which is the prerequisite for a reliable pollen classification in practical applications. MALDI imaging of laterally resolved pollen grains provides additional information by reducing the complexity of the MS spectra of mixtures, where frequently peak discrimination is observed. Combined with multivariate statistical analyses, such as principal component analysis (PCA), our approach offers the chance for a fast and reliable identification of individual pollen grains by mass spectrometry. Springer 2018 Journal of the American Society for Mass Spectrometry 29 11 2237 2247 10.1007/s13361-018-2036-5 2018-07-30 OPUS4-35296 Zeitschriftenartikel Seifert, Stephan; Weidner, Steffen; Panne, Ulrich; Kneipp, Janina Taxonomic relationship of pollen from MALDI TOF MS data using multivariate statistics Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been suggested as a promising tool for the investigation of pollen, but the usefulness of this approach for classification and identification of pollen species has to be proven by an application to samples of varying taxonomic relations. Chichester Wiley 2015 Rapid communications in mass spectrometry 29 1145 1154 10.1002/rcm.7207 2016-02-20 OPUS4-50482 Zeitschriftenartikel Diehn, S.; Zimmermann, B.; Tafintseva, V.; Seifert, S.; Bagcioglu, M.; Ohlson, M.; Weidner, Steffen; Fjellheim, S.; Kohler, A.; Kneipp, Janina Combining Chemical Information From Grass Pollen in Multimodal Characterization The analysis of pollen chemical composition is important to many fields, including agriculture, plant physiology, ecology, allergology, and climate studies. Here, the potential of a combination of different spectroscopic and spectrometric methods regarding the characterization of small biochemical differences between pollen samples was evaluated using multivariate statistical approaches. Pollen samples, collected from three populations of the grass Poa alpina, were analyzed using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, surface enhanced Raman scattering (SERS), and matrix assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The variation in the sample set can be described in a hierarchical framework comprising three populations of the same grass species and four different growth conditions of the parent plants for each of the populations. Therefore, the data set can work here as a model system to evaluate the classification and characterization ability of the different spectroscopic and spectrometric methods. ANOVA Simultaneous Component Analysis (ASCA) was applied to achieve a separation of different sources of variance in the complex sample set. Since the chosen methods and sample preparations probe different parts and/or molecular constituents of the pollen grains, complementary information about the chemical composition of the pollen can be obtained. By using consensus principal component analysis (CPCA), data from the different methods are linked together. This enables an investigation of the underlying global information, since complementary chemical data are combined. The molecular information from four spectroscopies was combined with phenotypical information gathered from the parent plants, thereby helping to potentially link pollen chemistry to other biotic and abiotic parameters. 2020 Frontiers in Plant Science 10 1788 urn:nbn:de:kobv:b43-504822 10.3389/fpls.2019.01788 https://creativecommons.org/licenses/by/4.0/deed.de 2020-03-02 OPUS4-39288 Zeitschriftenartikel Lauer, Franziska; Seifert, Stephan; Kneipp, Janina; Weidner, Steffen Simplifying the Preparation of Pollen Grains for MALDI-TOF MS Classification Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) is a well-implemented analytical technique for the investigation of complex biological samples. In MS, the sample preparation strategy is decisive for the success of the measurements. Here, sample preparation processes and target materials for the investigation of different pollen grains are compared. A reduced and optimized sample preparation process prior to MALDI-TOF measurement is presented using conductive carbon tape as target. The application of conductive tape yields in enhanced absolute signal intensities and mass spectral pattern information, which leads to a clear separation in subsequent pattern analysis. The results will be used to improve the taxonomic differentiation and identification, and might be useful for the development of a simple routine method to identify pollen based on mass spectrometry. Basel, Switzerland MDPI AG MDPI AG 2017 International Journal of Molecular Sciences 18 3 543 554 urn:nbn:de:kobv:b43-392885 10.3390/ijms18030543 http://creativecommons.org/licenses/by/3.0/de/deed.de 2017-03-07 OPUS4-41733 Zeitschriftenartikel Lauer, Franziska; Seifert, Stephan; Kneipp, Janina; Weidner, Steffen Simplifying the preparation of pollen grains for MALDI-TOF MS classification Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) is a well-implemented analytical technique for the investigation of complex biological samples. In MS, the sample preparation strategy is decisive for the success of the measurements. Here, sample preparation processes and target materials for the investigation of different pollen grains are compared. A reduced and optimized sample preparation process prior to MALDI-TOF measurement is presented using conductive carbon tape as target. The application of conductive tape yields in enhanced absolute signal intensities and mass spectral pattern information, which leads to a clear separation in subsequent pattern analysis. The results will be used to improve the taxonomic differentiation and identification, and might be useful for the development of a simple routine method to identify pollen based on mass spectrometry. MDPI 2017 International Journal of Molecular Sciences 18 3 543-1 543-11 10.3390/ijms18030543 2017-08-29 OPUS4-46529 Zeitschriftenartikel Diehn, Sabrina; Zimmermann, B.; Bagcioglu, M.; Seifert, Stephan; Kohler, A.; Ohlson, M.; Fjellheim, S.; Weidner, Steffen; Kneipp, Janina Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) shows adaption of grass pollen composition MALDI time-of-flight mass spectrometry (MALDI-TOF MS) has become a widely used tool for the classification of biological samples. The complex chemical composition of pollen grains leads to highly specific, fingerprint-like mass spectra, with respect to the pollen species. Beyond the species-specific composition, the variances in pollen chemistry can be hierarchically structured, including the level of different populations, of environmental conditions or different genotypes. We demonstrate here the sensitivity of MALDI-TOF MS regarding the adaption of the chemical composition of three Poaceae (grass) pollen for different populations of parent plants by analyzing the mass spectra with partial least squares discriminant analysis (PLS-DA) and principal component analysis (PCA). Thereby, variances in species, population and specific growth conditions of the plants were observed simultaneously. In particular, the chemical pattern revealed by the MALDI spectra enabled discrimination of the different populations of one species. Specifically, the role of environmental changes and their effect on the pollen chemistry of three different grass species is discussed. Analysis of the Group formation within the respective populations showed a varying influence of plant genotype on the classification, depending on the species, and permits conclusions regarding the respective rigidity or plasticity towards environmental changes. Nature 2018 Scientific Reports 8 1 16591, 1 11 urn:nbn:de:kobv:b43-465294 10.1038/s41598-018-34800-1 https://creativecommons.org/licenses/by/4.0/deed.de 2018-11-09