Wizard 2480 automatic gamma counter

Under isoflurane anesthesia, SD rats (n = 3, each time point) were decapitated at 20 and 60 min post injection of [¹⁸F]9. The blood and whole brain were then harvested immediately. The rat brain was cooled on ice, homogenized in 50% CH₃CN in H₂O on ice, and then centrifuged for 2.5 min at 4 °C (14,500×g). The supernatant was recovered. Similarly, the supernatant (0.5 mL) of blood samples was collected and mixed with ice-cooled CH₃CN (0.5 mL). The residue was vortexed for 20 s and again centrifuged for 2.5 min at 4 °C (14,500×g) for deproteinization. Both, brain and plasma homogenates were mixed with an aliquot of standard compound 9 (P10A-1910, 20 μL), and co-injected into the radio-HPLC system with a UV detector set on 264 nm. The samples were separated into ten sections (1 min for each section) using an analytical column (Phenomenex Luna C18, 250 mm × 10 mm, 5 μm), and with 70% CH₃CN in water as mobile phase for elution (5.0 mL/min). The radioactivity for each section was measured by a 2480 Wizard automatic gamma counter (PerkinElmer, USA), and the counts were all decay-corrected. The radiochromatograms were reconstructed, and the percentage of [¹⁸F]9 (standard UV peak as an indicator on HPLC) to total radioactivity was measured as [(counts for sections 6–9)/(total counts)] × 100.

ICR mice (male, 8 weeks, 25–30 g) were maintained on a 12 h light/12 h dark cycle and provided water ad libitum. 50 μCi (1.85 MBq) of [¹⁸F]9 (100 μL) was intravenously injected to each mouse via the tail vein. At the indicated time point, mice (n = 3) were sacrificed by dislocation of cervix, and organs such as whole brain, thymus, heart, liver, lungs, spleen, pancreas, stomach, small intestine, kidneys, bladder, testis, muscle, bone and blood samples were immediately collected and weighted. A 2480 Wizard automatic gamma counter (PerkinElmer, USA) was used for determining each organ's radioactivities, which were decay-corrected back to the [¹⁸F]9 injection time point according to the half-life of ¹⁸F.

cNIS⁻ and cNIS⁺ myoblasts were plated in quadruplicate in a 24-well plate for growth or differentiation. On the day of analysis, cells were incubated with ^{99 m}TcO₄⁻ (185 kBq) in 200 μL DMEM for 1 h, specific NIS inhibition was obtained by addition of 10 μM sodium perchlorate (NaClO₄) in some wells. Medium was collected, along with the PBS used to rinse the cells. Cells were collected, counted with a NucleoCounter NC-100 (ChemoMetec), and lysed. Radioactivity of the cells and of the media was measured by a 2480 Wizard automatic gamma counter (PerkinElmer). Uptake values were corrected for each sample according to the number of cells. Data were presented as mean ± SEM. One-way ANOVA was performed for in vitro radiotracer uptake experiment. p values < 0.05 were considered statistically significant.