Crc 15r dose calibrator

All reagents and solvents were purchased from commercial suppliers and were used without further purification. Triethylene glycol di-p-tosylate was synthesized following the procedures described in literature [19 (link)]. Thin layer chromatography (TLC) was performed on silica gel F₂₅₄ aluminum-backed plates (Merck, Darmstadt, Germany) with visualization under UV (254 nm). NMR spectra were recorded on a NMR spectrometer (Bruker, Germany) operating at 400 MHz for ¹H NMR spectra and 100 MHz for ¹³C NMR spectra at Instrumentation Resource Center of National Yang-Ming University. All chemical shift values were reported in ppm (δ). Electrospray ionization-mass spectra (ESI-MS) were acquired on a FINNIGAN LCQ mass spectrometer at Instrumentation Resource Center of National Taiwan University. Analytic as well as semipreparative high performance liquid chromatography (HPLC) was performed with a Waters 600E pump equipped with a Waters 2998 photodiode array detector and a flow count radio detector (Bioscan, Washington DC) for gamma ray detection. Radioactivity was assayed using a Capintec CRC-15R dose calibrator (Ramsey, NJ) or a γ-scintillation counter (Wallac 1470 Wizard automatic gamma counter, Perkin-Elmer, Waltham, MA).

Fluorine-18 labeled [¹⁸F]Flotaza [10 (link)], [¹²⁵I]IBETA [11 (link)] and iodine-125 labeled [¹²⁵I]IPPI [9 ] were prepared as reported previously. Capintec CRC-15R dose calibrator and Capintec Caprac-R well-counter (Florham Park, NJ, USA) were used for radioactivity measurements. Thin layer chromatography of radioligands was scanned on an AR-2000 imaging scanner (Eckart and Ziegler, Berlin, Germany). Cyclone phosphor autoradiographic imaging system (Perkin Elmer Inc, Shelton, CT, USA) and Optiquant Imaging System software were used for analysis. Immunostaining of brain sections was carried out by UCI Pathology core services. QuPath (version QuPath—0.2.3) was used for quantitative analysis of scanned brain slices.

General methods were similar to those described previously [14 ,16 (link),19 (link)]. Iodine-125 sodium iodide was purchased from American Radiolabeled Chemicals, Inc., St. Louis, MO, USA (Iodine-125 sodium iodide, carrier-free (specific activity = 643 MBq/μg) in 0.01 N NaOH). Iodine-125 radioactivity was counted in a Capintec CRC-15R dose calibrator, while low-level counting was carried out in a Capintec Caprac-R well-counter. RadioTLC was scanned on an AR-2000 imaging scanner (Eckart & Ziegler, Berlin, Germany). Electrospray mass spectra were obtained from a Model 7250 mass spectrometer (Micromass LCT). Proton NMR spectra were recorded on a Bruker OM EGA 500-MHz spectrometer.

All instruments were calibrated and
maintained according to the standard quality control practices and
procedures. UV–vis measurements were taken on a Shimadzu BioSpec-nano
microvolume UV–vis spectrophotometer (Shimadzu Scientific Instruments;
Kyoto, Japan). Radioactivity measurements were taken using a CRC-15R
dose calibrator (Capintec, Inc.; Ramsey, NJ, USA) and an automatic
Wizard²gamma counter (PerkinElmer; Waltham, MA, USA). Surface
plasmon resonance was performed using a Nicoya OpenSPR-XT instrument
(Nicoya Lifesciences; Kitchener, ON, Canada).

⁸⁹Zr in 1 M oxalic acid was purchased from 3D imaging (Little Rock, AR). Activity measurements were performed using a Capintec CRC-15R Dose Calibrator (Capintec, Ramsey, NJ).