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 - JOUR A1 - Müller, Larissa A1 - Mairinger, T. A1 - Hermann, G. A1 - Koellensperger, G. A1 - Hann, S. T1 - Characterization of metal-tagged antibodies used in ICP-MS-based immunoassays N2 - A detailed characterization of metal-tagged antibodies is the prerequisite for the implementation of quantitative concepts in inductively coupled plasma–mass spectrometry (ICP-MS)-based bioanalysis or future medical diagnosis. In this paper, the common modification with bifunctional ligands containing maleimide residues as a reactive group was investigated in detail via size exclusion chromatography (SEC)-ICP-MS and liquid chromatography–time-of-flight (LC-TOF)-MS to determine the preservation of the antibody structure after tagging. Mouse monoclonal IgG modified with metal-coded tags (MeCATs) was used as a model system. Several antibody fragments were identified carrying different numbers of metal tags. In a second step, a functionality test was performed with isolated fragments where the antigen specificity was tested in a dot blot immunoassay. KW - Bioanalytical methods KW - Mass spectrometry KW - ICP-MS KW - Antibody tagging KW - Antibodies KW - Immunoassay KW - Maleimide DOTA KW - Tags PY - 2014 U6 - https://doi.org/10.1007/s00216-013-7416-x SN - 1618-2642 SN - 1618-2650 VL - 406 IS - 1 SP - 163 EP - 169 PB - Springer CY - Berlin AN - OPUS4-30037 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -