The peptide samples were desalted with a reversed-phase mini column cartridge (SepPak Light C18 cartridges, Waters, Milford, MA).
Briefly, once transferred into a dedicated (ventilated and lead-shielded) hot cell, [18F] fluoride was first trapped on a preconditioned Sep-Pak® Accell Plus QMA Light cartridge (Waters, Milford, MA, USA) and subsequently eluted from the cartridge with a solution of Kryptofix K2.2.2/K2CO3 in a mixture of water and acetonitrile.
The product fraction was additionally purified using a SepPak Alumina N light cartridge.
After purification via one Sep-Pak C8 light cartridge, the ethanolic product fraction was diluted with PBS and used as such for the experiments.
18F-fluoride was trapped with an ion-exchange resin QMA sep-pak light cartridge and eluted from the resin by 210 mmol/L K2CO3 solution (0.2 mL) and 31 mg/mL Kryptofix 2.2.2 in acetonitrile solution (K222, 0.7 mL).
The desired fraction (10 11 min for [18F] DPA-714, 12 13 min for [18F] VUIIS1008) was collected, diluted with water (20 mL), and the radiotracer was retained on a C-18 cartridge (Sep-Pak® Light, Waters, Milford, MA, USA) and further eluted with ethanol (1 mL).
The radiotracer was isolated by semi-preparative HPLC (Reprosil-Pur AQ column, 250×10mm, 46 % ACN/aqu. 20 mM NH4OAc, flow 5.5 ml/min) followed by purification with a Sep-Pak C18 Plus light cartridge and formulation in isotonic saline containing 10% ethanol.
The Ga-labeled conjugate, Gd6 L[c(RGDyK)]3Ga, was purified by passing the mixture through a preconditioned Sep-Pak C-18 light cartridge.
The Gd6 LGa complex was purified by passing the mixture through a preconditioned Sep-Pak C-18 light cartridge.
Press the pins on the reset tool firmly against the chip contacts on the ink cartridge until the light on the reset tool begins to blink red.
