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 OPUS4-27986 Zeitschriftenartikel Weidner, Steffen; Schultze, R.-D.; Enthaler, B. Matrix-assisted laser desorption/ionization imaging mass spectrometry of pollen grains and their mixtures RATIONALE The fast and univocal identification of different species in mixtures of pollen grains is still a challenge. Apart from microscopic evaluation and Raman spectroscopy, no other techniques are available. METHODS Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry was applied to the analysis of extracts of single pollen grains and pollen mixtures. Pollen grains were fixed, treated and covered with matrix directly on the MALDI target. RESULTS Clearly resolved MALDI ion intensity images could be obtained enabling the identification of single pollen grains in a mixture. CONCLUSIONS Our results demonstrate the potential and the suitability of MALDI imaging mass spectrometry as an additional method for the identification of pollen mixtures. Chichester Wiley 2013 Rapid communications in mass spectrometry 27 8 896 903 10.1002/rcm.6523 2016-02-20 OPUS4-36837 Vortrag Weidner, Steffen Multivariate statistics applied to MALDI-TOF MS data of pollen samples Pollen represent one major cause for human allergic diseases. Currently the characterization and identification of pollen is time-consuming since it mainly relies on the microscopic determination of the genus-specific pollen morphology. A variety of new analytical approaches, like Raman - and fluorescence spectroscopy have been proposed in order to develop fast and reliable pollen identification. Recently matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was initially applied for the rapid investigation of such complex biological samples. Taxonomic differences and relations of single pollen grains could be identified. Both commercially available lyophilized pollen and fresh pollen acquired from biological samples collected in parks and in the Botanical Garden Berlin in the years 2013-2015 were investigated. The samples were prepared by formic acid extraction in the gas phase and spotted with HCCA matrix. A variety of new approaches, like a newly developed MALDI target with micrometer sample spots sizes, were tested for their suitability. The obtained mass spectral data were investigated by principal component analysis (PCA). The applicability of MALDI-TOF mass spectrometry for the classification of pollen according to their taxonomic relationships was proven. Specifically, chemical differences in the mass spectra at the levels of plant order, genus and in many cases even of species could be identified. Based on these results, further investigations have been undertaken to optimize the sample preparation for the classification of single pollen grains in mixtures of pollens. A novel MALDI-target design was developed to enhance the phenotypic information of pollens in their mass spectra. The combination of mass spectral patterns and multivariate statistics provide a powerful tool for the investigation of structural correlations within mixtures. The results can be used to improve the reconstruction of taxonomic relations of single species in various mixtures and might be useful for the development of a fast routine method to identify pollen based on mass spectrometry. 2016 64th ASMS Conference on Mass Spectrometry and Allied Topics San Antonio, TX, USA 05.06.2016 09.06.2016 2016-07-12 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