Gamma spectroscopy involves analyzing the energy spectrum of gamma rays emitted by targeted atoms present in the sample to be identified. It uses detectors to capture and measure these gamma rays, producing detailed information about the levels of radioactivity present in a sample and its composition. The commonly available detectors are high-purity germanium (HPGe) gamma spectrometer, LaBr3 gamma spectrometer, and NaI (Tl) gamma spectrometer of which semiconductor-based HPGe’s are the most advanced types due to their extensive range of energies and are used for a variety of applications. However, cryogenic cooling is required for such semiconductor-based detectors and two options are available, the first option cooling via standard liquid Nitrogen and the second method by integrated electro-mechanical cryocoolers (ICS). This liquid Nitrogen-free ICS employs the latest generation technology and is now available in two versions, the ICS-E model and the ICS-P4 PopTop model. Both ICS models are highly reliable, have low maintenance, and are mechanically cooled; however, the proposed ICS-P4 PopTop model has better compatibility is portable, and can deliver superior performance in executing transformative multi-disciplinary research.
This state-of-the-art Spectrometer enables us to study transport processes in syncytia: A syncytium, or a multinucleated tissue sharing a cytoplasm, requires various transport pathways (both active and passive) to allow for RNA, protein, and other biological molecules to move throughout the structure. Skeletal muscle, cardiac muscle, smooth muscle, syncytiotrophoblast in placenta, and fungi in yeast are examples of syncytium. At MU, research is skeletal muscle engineering. In skeletal muscle, the localizations, mechanisms of transport, and roles of these localized pools of RNA, protein, and other biological molecules throughout the structure of syncytium are yet to be elucidated (Pinheiro et al, 2021; Danes et al, 2021, Bagley et al, 2023).
Several techniques have been utilized to assess the localizations of RNA, protein, and other biological molecules (immunolabeling, fluorescence reporter tagging, in-situ hybridization, and single-cell sequencing). However, several of these techniques cannot be utilized in a real-time fashion, such as in-situ hybridization utilized by both Pinheiro et al, 2021 and Danes et al, 2021, in which only a snapshot is visualized using fixed, permeabilized fibers. Techniques such as the MS2 system, as utilized by Danes et al, 2021, allow for live cell RNA dynamics to be assessed. However, it requires genetic manipulation, with high costs and technical demands. Dyes that label RNA such as SytoRNA Select allow for labeling of RNA in real time. However, the specificity of this labeling and the signal-to-noise ratio is limited as it can also bind to DNA.
We propose to utilize radioactively labeled amino acids (such as 3H-Leucine), and ³²P and ³²S nucleotides to assess the spatial distribution of proteins and RNA in syncytium (i.e. skeletal muscle) to characterize transport processes. Specifically, we will elucidate the mechanisms of transport as skeletal muscle precursor cells (C2C12 cells, a murine model of myoblasts) fuse to form multinucleated myotubes. We will be measuring the uptake of these radionuclides using the gamma-ray spectrometer (HPGe-ICS P4). We will extend this work by characterizing the impact of proteins in various pathways (such as YAP/TAZ in Hippo pathway, and microtubules) by genetic and pharmacological manipulations. Furthermore, we will assess how estrogen and other hormones impact this process through radiolabeling of estrogen and other hormones  [18F]-fluoroestradiol ([18F]-F-FES).
This research will be further expanded to look at the impact of transport processes in a bacterial biofilm. Staphylococcus epidermidis is susceptible to the antibiotic vancomycin in a planktonic state. However, in a biofilm, 75% of these bacteria are resistant to the same antibiotic.  The transport mechanisms in this biofilm are still being elucidated. We will further examine this mechanism by utilizing radioactive labeling.  This resistance mechanism will be further elucidated using [18F]-fluorodeoxyglucose ([18F]-FDG),[18F]-fluoroestradiol ([18F]-F-FES),  radioactively labeled amino acids (such as 3H-Leucine), and ³²P and ³²S nucleotides in bacterial biofilms.