Customer Success Stories
Maestro: In Vivo Fluorescence Imaging
Issue: How to provide high-sensitivity and versatile in vivo fluorescence imaging capabilities in a core small animal imaging facility.
Solution: The Maestro™ small animal imaging system provided the needed easy-to-use, rapid, flexible and highly sensitive optical imaging system required of a core facility.
Unlike individual research laboratories, core facilities must provide solutions that are versatile enough to serve the broad range of applications and requirements of their scientific community, yet perform to the rigorous specifications necessary to generate useful data. Dr. Ralph Mason, Professor of Radiology, and director of a UTSWMC Imaging Core facility, knows this issue well. Dr. Mason runs a very well-equipped facility that provides state-of-the-art imaging systems and software for all aspects of small animal imaging. He was tasked with finding an in vivo fluorescence imaging system that was both sensitive enough, yet time-efficient in order to help deal with the large volume of researchers who needed that modality of imaging. Dr. Mason tested various models, and finally decided upon the Maestro system because of its speed and its ease-of-use, but primarily because of the dramatic increase in sensitivity and quantitative accuracy compared with other systems.
The Maestro system in Dr. Mason's laboratory has been used for a wide variety of challenging applications, ranging from imaging GFP in deep tissues such as the liver to the imaging of the distribution of antibodies labeled with NIR fluorophores to the development of fluorescent nanoparticles. Because of the laboratories interest in pharmacokinetics and the dynamics of fluorophore distributions, it is the quantitative aspects of the Maestro system that are of importance to the majority of the projects in the imaging center (Figure 1). Autofluorescence had always been a confounding factor for quantitation in in vivo fluorescence imaging, limiting sensitivity and adding an unknown amount of unwanted signal to each measurement - the Maestro system changed all of that, enabling sensitive and quantitative imaging results down to much lower, and therefore more useful, levels of signal. Dr. Mason's interest in pharmacokinetics and fluorophore dynamics along with his experience in dynamic imaging in MR, PET and other modalities has also led him to be one of the early testers of CRi's DyCE™ (Dynamic Contrast Enhancement) technology, which will allow him to explore rapid temporal changes in fluorophore concentrations and the differences between these distributions in normal and pathological conditions in mice.
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Figure 1: Optical Imaging of Exposed Phosphatidylserine in Tumors. a) Unmixed images of the nude mouse injected with control C44-SAIVI 680 and B2GP1 (a1, pre injection; a2, 2 days after IV injection; a3, 6 days after IV injection). b) Unmixed images of the nude mouse injected with 2aG4-SAIVI 680 and B2GP1 (b1, pre injection; b2, 2 days after IV injection; b3, 6 days after IV injection). Note: the images were processed by 4-way unmixing (food, skin, and tumor signals at days 2 and 6) and then adding the food and skin together, and adding the two tumor images together. c) Normalized emission spectra for A(C1) and B (C2). White: skin; Yellow: food; Green: 2 day tumor; Blue: 6 day tumor.
The Maestro in vivo imaging system and related solutions are the perfect addition to core imaging facilities and central laboratories because of the flexibility, sensitivity and quantitative imaging capabilities. In addition, because of its ease-of-use, researchers with a wide range of backgrounds and experiences can easily obtain results that would be considered unobtainable on any other system.
