Radiomatic 150tr radioisotope detector

⁶⁸Ga was obtained from a ⁶⁸Ge/⁶⁸Ga generator (Eckert & Ziegler, Valencia, CA, USA) by elution with 0.1 M HCl. ⁶⁸Ga eluate (0.5 mL, 280 − 360 MBq) was mixed with 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid (HEPES, 120 mg) to give a pH of approximately 4.1. DOTA-Siglec-9 peptide (5 − 35 nmol, 12 − 85 μg, dissolved in deionized water to give a stock solution of 1 mM; Peptide Specialty Laboratories GmbH, Heidelberg, Germany) was added, and the reaction mixture was heated at 100 °C for 15 minutes. No further purification was performed. The radiochemical purity of ⁶⁸Ga-DOTA-Siglec-9 was determined by radiodetector-coupled reversed-phase high-performance liquid chromatography (radio-HPLC) (Jupiter C18 column, 4.6 × 150 mm, 300 Å, 5 μm; Phenomenex, Torrance, CA, USA). The HPLC conditions were as follows: flow rate = 1 mL/minute; λ = 215 nm; A = 0.1 % trifluoroacetic acid (TFA)/water; B = 0.1 % TFA/acetonitrile; gradient: during 0 − 2 minutes 82 % A and 18 % B; during 2 − 11 minutes from 82 % A and 18 % B to 40 % A and 60 % B; during 11 − 15 minutes from 40 % A and 60 % B to 82 % A and 18 % B; during 15 − 20 minutes 82 % A and 18 % B. The radio-HPLC system consisted of LaChrom Instruments (Hitachi; Merck, Darmstadt, Germany) and of a Radiomatic 150TR radioisotope detector (Packard, Meriden, CT, USA). ¹⁸F-FDG was synthesized as described previously [17 (link)].

1,4,7-Triazacyclononane-1-glutaric acid-4,7-diacetic acid conjugated RGD peptide (cyclo[L-arginylglycyl-L-a-aspartyl-d-tyrosyl-N6-([[4,7-bis(carboxymethyl)-1,4,7-triazonan-1-yl]acetyl])-l-lysyl]; NODAGA-RGD) was purchased from ABX advanced biochemical compounds GmbH (product number 9805; Radenberg, Germany). ⁶⁸Ga was obtained from a ⁶⁸Ge/⁶⁸Ga generator (Eckert & Ziegler, Valencia, CA, USA) by elution with 0.1 M hydrochloric acid. ⁶⁸Ga-eluate (500 μl) was mixed with sodium acetate (18 mg) to give a pH of approximately 5. Then, NODAGA-RGD (10 nmol, dissolved in deionized water to give stock solution of 1 mM) was added. The reaction mixture was heated at 100 °C for 15 min. No further purification was performed. The radiochemical purity of [⁶⁸Ga]NODAGA-RGD was determined by reversed-phase high-performance liquid chromatography (RP-HPLC) with a Jupiter C18 column (4.6 × 150 mm, 300 Å, 5 μm; Phenomenex, Torrance, CA, USA). The HPLC conditions were as follows: flow rate = 1 ml/min, λ = 220 nm. The gradient system was: A = 0.1% trifluoroacetic acid (TFA) in water; B = 0.1% TFA in acetonitrile. The A/B gradient was: 0–5 min 97/3, 5–15 min from 97/3 to 0/100. The HPLC system consisted of LaChrom Instruments (Hitachi; Merck, Darmstadt, Germany) coupled with a flow-through Radiomatic 150TR radioisotope detector (Packard, Meriden, CT, USA).