TY - JOUR A1 - Giesen, Charlotte A1 - Müller, Larissa A1 - Mairinger, T. A1 - Drescher, Daniela A1 - Kneipp, Janina A1 - Roos, P.H. A1 - Panne, Ulrich A1 - Jakubowski, Norbert T1 - Iodine as an elemental marker for imaging of single cells and tissue sections by laser ablation inductively coupled plasma mass spectrometry N2 - A new laser ablation (LA)-ICP-MS method for single cell and cell nucleus imaging was developed. Therein, iodine was employed as an elemental dye for fibroblast cells and for thin tissue sections. At an incubation time of 60 s, iodine is located mainly within the cell nuclei. This effect was illustrated in fibroblast cells, and iodine signal within the cell nucleus was as high as 5 × 104 cps at 4 µm laser spot size. The surrounding cytoplasm was iodinated as well, but to a lesser extent. The spatial resolution attained was sufficient to detect even smaller cell nuclei within a liver biopsy tissue. Furthermore, iodine was successfully employed for biomolecule labeling and we demonstrated that iodine signal increased with increasing thickness of a palatine tonsil tissue. Thus, the use of iodine as an internal standard to correct for tissue inhomogeneities in LA-ICP-MS was investigated for the simultaneous detection of two tumor markers (Her 2 and CK 7) in breast cancer tissue. Additionally, lanthanide background resulting from glass ablation can be corrected for by Eu standardization. PY - 2011 U6 - https://doi.org/10.1039/c1ja10227c SN - 0267-9477 SN - 1364-5544 N1 - Geburtsname von Müller, Larissa: Wäntig, L. - Birth name of Müller, Larissa: Wäntig, L. VL - 26 IS - 11 SP - 2160 EP - 2165 PB - Royal Society of Chemistry CY - London AN - OPUS4-24964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Giesen, Charlotte A1 - Mairinger, T. A1 - Khoury, L. A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Multiplexed immunohistochemical detection of tumor markers in breast cancer tissue using laser ablation inductively coupled plasma mass spectrometry N2 - We optimized multiplexed immunohistochemistry (IHC) on breast cancer tissue. Up to 20 tumor markers are routinely evaluated for one patient, and thus, a common analysis results in a series of time consuming staining procedures. As an alternative, we used lanthanides for labeling of primary antibodies, which are applied in IHC. Laser ablation (LA) ICPMS was elaborated as a detection tool for multiplexed IHC of tissue sections. In this study, we optimized sample preparation steps and LA ICPMS parameters to achieve a sufficient signal-to-background ratio. The results prove the high selectivity of applied antibodies, which was sustained after labeling. Up to three tumor markers (Her 2, CK 7, and MUC 1) were detected simultaneously in a single multiplex analysis of a 5 µm thin breast cancer tissue at a laser spot size of 200 µm. Furthermore, the LA ICPMS results indicate a significantly higher expression level of MUC 1 compared to Her 2 and CK 7, which was not obvious from the conventionally stained tissue sections. PY - 2011 U6 - https://doi.org/10.1021/ac2016823 SN - 0003-2700 SN - 1520-6882 N1 - Geburtsname von Müller, Larissa: Wäntig, L. - Birth name of Müller, Larissa: Wäntig, L. VL - 83 IS - 21 SP - 8177 EP - 8183 PB - American Chemical Society CY - Washington, DC AN - OPUS4-24966 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Hayen, H. A1 - Roos, P. H. T1 - Method development for iodination of proteins for LA-ICP-MS based proteomics T2 - European Winter Conference on Plasma Spectrochemistry CY - Zaragoza, Spain DA - 2011-01-30 PY - 2011 N1 - Geburtsname von Müller, Larissa: Wäntig, L. - Birth name of Müller, Larissa: Wäntig, L. AN - OPUS4-23821 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Hayen, H. A1 - Roos, P.H. T1 - Iodination of proteins, proteomes and antibodies with potassium triodide for LA-ICP-MS based proteomic analyses N2 - A fast and mild method for iodine labelling of proteins is presented which is specifically designed and optimized for laser ablation (LA-)ICP-MS based proteomics. Single proteins (lysozyme, bovine serum albumin, cytochrome c and β-casein), whole proteomes (microsomal proteome of rats) and antibodies (anti-bovine casein, anti-bovine serum albumin) can be efficiently iodinated by means of potassium triiodide with minimal losses of antigen properties and antibody binding to iodinated proteins. A comparison with iodination by use of IODO-Beads is presented and it is shown that triiodide labelling is a fast, cheap and less laborious alternative without compromising the analytical figures of merit. PY - 2011 U6 - https://doi.org/10.1039/c1ja10090d SN - 0267-9477 SN - 1364-5544 N1 - Geburtsname von Müller, Larissa: Wäntig, L. - Birth name of Müller, Larissa: Wäntig, L. VL - 26 SP - 1610 EP - 1618 PB - Royal Society of Chemistry CY - London AN - OPUS4-24209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Hösl, Simone A1 - Scheler, Ch. A1 - Roos, P.H. T1 - Development of multiplex immunoassays for protein detection by Laser Ablation (LA-) ICP-MS T2 - Third International Symposium on Metallomics CY - Münster, Germany DA - 2011-06-15 PY - 2011 N1 - Geburtsname von Müller, Larissa: Wäntig, L. - Birth name of Müller, Larissa: Wäntig, L. N1 - Geburtsname von Hösl, Simone: Hardt, S. - Birth name of Hösl, Simone: Hardt, S. AN - OPUS4-24110 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Larissa A1 - Jakubowski, Norbert A1 - Roos, P.H. T1 - Multi-parametric analysis of cytochrome P450 expression in rat liver microsomes by LA-ICP-MS N2 - Quantitative analysis of cytochrome P450 (CYP) patterns of cells and tissues is an important aspect in toxicological and pharmacological research as this group of enzymes is largely involved in the metabolism of toxic compounds and drugs. Here we present a method for the multi-parametric and simultaneous quantitative determination of several cytochromes P450 in liver microsomes of untreated and inducer treated rats. The method is based on the binding of specifically lanthanide labelled antibodies to electrophoretically separated and blotted CYP proteins and their subsequent identification and quantification by LA-ICP-MS. CYP1A1, CYP2B1, CYP2C11, CYP2E1 and CYP3A1 were simultaneously quantified and the patterns between microsomal samples were compared. Microsomes of rats treated with 3-methylcholanthrene, phenobarbital and dexamethasone showed increased levels of CYP1A1, CYP2B1 and CYP3A1, respectively. These results coincide with data obtained by independent methods for CYP quantification, i.e. ethoxyresorufin O-deethylase activity for CYP1A1 and pentoxyresorufin O-depentylase for CYP2B1. The presented method is useful for multi-parametric CYP profiling and has further large potential with respect to the number of analysed parameters/proteins and sensitivity. PY - 2011 U6 - https://doi.org/10.1039/c0ja00077a SN - 0267-9477 SN - 1364-5544 N1 - Geburtsname von Müller, Larissa: Wäntig, L. - Birth name of Müller, Larissa: Wäntig, L. VL - 26 IS - 2 SP - 310 EP - 319 PB - Royal Society of Chemistry CY - London AN - OPUS4-23465 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -