Confocal Laser Scanning Microscope System for Sample Analysis in Horizontal and Vertical Orientation

• Subject Area: Agriculture, Forestry and Veterinary Medicine
• Term: Funded in 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 560844837

The plant science community at the Martin Luther University (MLU) applies for a versatile, sensitive, and fast Confocal Laser Scanning Microscope system that allows to analyse samples in horizontal and vertical object orientation (hvCLSM). The system is urgently required by the groups of Plant Nutrition and Crop Physiology at the Institute of Agricultural and Nutritional Sciences, General Botany and General Genetics at the Institute of Biology, Plant Biochemistry at the Institute of Biochemistry, as well as by a number of additional users at all institutes of the MLU concerned with plant science. Projects in these groups address a large variety of biological questions that require capabilities of a hvCLSM system that cannot be met by existing CLSM instruments. The imaging tasks include the detection and quantification of fluorescence proteins and dyes to analyse the localisation and movement of proteins, lipids, and organelles, determine gene expression, and visualize cellular parameters, such as free ion concentrations (e.g., Ca2+), pH, ROS, or phytohormones. The vertical stage option of the hvCLSM system is required to allow the observation of specimens in the state of the natural gravistimulus, i.e. in upright specimen orientation. This prevents the interference of gravistimulation with responses to stimuli to be studied, such as temperature or salt, and, in conjunction with region-of-interest tracking software, it allows long-term studies of root development and root-microbe interactions. In vertical sample orientation, primarily plant roots or hypocotyls will be analysed as whole mount specimens, the imaging of which requires a long-working distance condensor and respective objectives. In horizontal sample orientation, either in combination with or independent of vertical analyses, images will be recorded from a variety of sample types, e.g. protoplasts, pollen tubes, sections, or whole mount leaves and roots. The system must allow quantitative analyses of sub-cellular compartments, organelles, and structures in these specimens at resolution beyond the Abbe limit and with simultaneous detection and sharp separation of multiple fluorophores with overlapping emission spectra and similar lifetime, which will be met by a high-resolution detection system with spectral unmixing. To allow for a highly efficient operation, the system must have an automatic sample detection facility. If it is not possible to switch directly from horizontal to vertical orientation in one stand, alternative proposals for the realisation of a hvCLSM system must be offered that ensure adequate analysis of vertical and horizontal orientations of the samples. It must be ensured that a given structure of the respective sample can be analysed horizontally and vertically with pinpoint accuracy (e.g. by coordinate transfer) and in immediate succession.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Konfokales Laser-Scanning-Mikroskopsystem zur Analyse horizontal und vertikal orientierter Proben
• Instrumentation Group: 5090 Spezialmikroskope
• Applicant Institution: Martin-Luther-Universität Halle-Wittenberg
• Leader: Professor Dr. Edgar Peiter