In vivo fluorescence imaging is being used to optimize biomarkers for PET and assist in longitudinal studies. An in vivo Kodak imaging system F (Image Station 4000MM) is used for these studies. The system features 5-position excitation filter slider with two excitation filters of choice, 4-position emission filter wheel with two proprietary wide-angle emission filters of choice, external 150-watt halogen illumination source and mounted fiber-optic light guides, PC computer with 17-inch flat-panel monitor, KODAK Molecular Imaging Software. The CCD camera presents 4.2 megapixel resolution, true 16-bit imaging and high sensitivity.
Multimodality Imaging Probe: Structure of BSA-Biotin-DTPA-FAM during the process of radiochelation with 68GaCl3 to form BSA-Biotin-DTPA-FAM-68Ga. 
Imaging of rodents with Multimodality probe: Left: Fluorescence Image: Bright spots at both flanks: one for FAM conjugate (50µL) and other for FAM-68Ga conjugate (50µL). Right: MicroPET image: only one hot spot at the expected flank (FAM-68Ga conjugate 30µCi; 25µCi of 18F was also injected (iv) for skeletal uptake).
Potential Fluorescence Imaging Agents for α4β2 nicotinic receptors: A. Minimized energy structure of nifrolidine, 3 with reported high affinity for a4b2* receptors; B. Energy minimized structure of nifrodansyl, 4, in which the fluorine atom in 3 is replaced with the fluorescent moiety, dansylamide (marked in green bracket in 4). C. Energy minimized structure of nifrofam, 5, in which the fluorine atom in 3 is replaced with the fluorescent moiety, carboxyfluorescein (FAM, marked in green bracket in 5).
α4β2HA stable cells – live labeling and live cell imaging: HEK cells stably expressing α4β2HA nicotinic receptor subtypes were untreated (top panel, A-C) or treated with nicotine (10 mM for 17 hr; bottom panel, D-F). Nicotine was washed off prior to labeling the live cells with antibody or ligand. Cell surface receptors were labeled with anti-HA (b2 subunit has an HA tag at the extracellular C-terminus tail) followed by Nifrofam (100 nM) and Alexa Fluor 568 anti-rabbit secondary antibody.
