2470 wizard automatic gamma counter

Positron Emission tomography (PET)/computed tomography (CT) imaging was conducted in C57BL/6 and Dectin-1^−/− mice 48 h after IP injection of 1 mg of pure ⁸⁹Zr-WGP or injection of 1 × 10⁶ peritoneal macrophages that had been co-cultured with 25 μg/ml of ⁸⁹Zr-WGP for 2 h and then gently washed to remove excess ⁸⁹Zr-WGP. The mice were scanned for 15 min with a Siemens R4 MicroPET followed by 10 min of CT scan. Siemens IAW software was used for the acquisition and reconstruction of the PET signal, and Siemens IRW software was used for merging and analyzing the imaging data. At the end of the imaging study, mice were euthanized, and organs of interest were harvested. For biodistribution, 50 uL of peripheral blood was collected using a retro-bulbar bleeding technique. The brain, heart, lungs, liver, spleen, kidneys, pancreas, large intestine, small intestine, stomach, femur, a piece of skin from the flank of the mice, and the rectus femoris muscle were harvested, weighed, and placed in a 2470 Wizard automatic gamma counter (PerkinElmer) in order to measure the radioactivity of each tissue. The CPM values were calculated using Prism software (GraphPad Software, La Jolla, CA).

All applicable institutional and/or national guidelines for the care and use of animals were followed.
The physiological distribution of ^99mTc-HYNIC-PMB was determined in healthy C57BL/6 mice (female, 6–10 weeks old, Envigo). Approximately 1.85 MBq (50 µL, 0.1 mg) of radiolabeled PMB was injected in the lateral tail vein of mice. The exact injected activity was calculated by dilution of the original sample and weighing the syringe before and after sampling and after injection. All syringes used were without dead volume (BD Micro-FineTM+). Images were acquired under anesthesia using a high resolution γ-camera (Li-Tech, Italy) [27 (link)] for 25 s at 1, for 31 s at 3 h and for 45 s at 6 h.
After each time point, four mice were sacrificed; blood samples and major organs (small bowel, large bowel, kidneys, spleen, stomach, liver, muscle, bone, lungs and salivary glands) were collected and weighted for ex-vivo studies. The radioactivity in each vial was counted in a single-well gamma counter (2470 Wizard Automatic Gamma Counter, PerkinElmer, Waltham, MA, USA).
Radioactivity in all organs was expressed as percentage of injected dose per organ (%ID) and percentage of injected dose per gram (%ID/g).

[⁵⁷Co]Co-chloride was purchased from PerkinElmer (Upplands Vasby, Sweden). ⁵⁵Co and ⁶⁴Cu were produced in-house at Odense University Hospital as previously described [44 (link),55 (link)]. In one instance, the ⁶⁴Cu was purchased at DTU NuTech, Technical University of Denmark. The GRPR antagonists NOTA-PEG₂-RM26 and NODAGA-PEG₂-RM26 were synthesized as described earlier [26 (link)]. Buffers for radiolabeling were produced in-house from chemicals supplied by Merck (Darmstadt, Germany) and were pretreated with Chelex 100 resin (Bio-Rad Laboratories, Hercules, CA, USA) to remove metal contaminants. Other chemicals were purchased from Sigma-Aldrich Sweden (Upplands Vasby, Sweden). Radioactive samples were measured in an automated gamma-counter (2470 Wizard Automatic Gamma Counter, Perkin-Elmer).
PC-3 human PC cell line expressing GRPR was purchased from ATCC, LGC Promochem. Cells were cultured in RPMI-1640 media supplemented with 10% fetal calf serum (Sigma), PEST (penicillin 100 IU/mL, streptomycin 100 g/mL), and 2 mM l-glutamine (all from Biochrom AG, Berlin, Germany). This medium is referred to in the text as complete medium. Trypsin-EDTA (0.05% trypsin, 0.02% EDTA in buffer) was purchased from Biochrom AG.

Forty thousand freshly sorted cells were incubated with 18.5 kBq/mL [¹²⁵I]I-UdR (prepared as in [36 (link)] in 1 mL serum-free medium for 1, 4, and 7 h in non-adherent 24-well plates). At each time point, the cells were washed twice with 400 µL cold PBS and 400 µL 5% trichloroacetic acid (TCA). The pelleted DNA was solubilized in 500 µL NaOH. The radioactivity in the TCA fractions and collected DNA was determined in a 2470 Wizard Automatic Gamma Counter (Perkin Elmer, Skovlunde, Denmark). Cellular uptake was given by the sum of radioactivity in the TCA fractions and collected DNA relative to added radioactivity (% of injected dose/well). The DNA incorporation was calculated as the percentage of radioactivity in the DNA relative to added radioactivity (% of injected dose/well).