A. Kostikov, J. Chin, Katy Orchowski
Oct 4, 2012
Citations
0
Influential Citations
23
Citations
Journal
Nature Protocols
Abstract
N-Succinimidyl 3-(di-tert-butyl[18F]fluorosilyl)benzoate ([18F]SiFB) is a highly reactive prosthetic group for radiolabeling of proteins for use in positron emission tomography (PET). It is similar to N-succinimidyl-4-[18F]fluorobenzoate ([18F]SFB), the 'gold-standard' prosthetic group for protein 18F-labeling, but can be synthesized using a much shorter and technically easier procedure. A recently reported simple procedure to obtain anhydrous 18F− by avoiding time-consuming azeotropic drying is applied with a slight modification to prevent basic hydrolysis of the active N-hydroxysuccinimide (NHS) ester moiety of [18F]SiFB. The labeling of [18F]SiFB is performed by a fast 18F–19F isotopic exchange (IE) reaction at room temperature (20–25 °C) within 30 min. [18F]SiFB is purified using a C18 cartridge instead of HPLC, further decreasing the overall time required for protein labeling. High specific activities >18.5 GBq μmol−1 (>500 Ci mmol−1) can be obtained. Finally, incubation of [18F]SiFB with the desired protein in an aqueous solution at pH 9, followed by HPLC purification, provides the final solution of the labeled protein ready for in vivo applications.