Gallium-68 ((68)Ga) is a generator-produced radionuclide with a short half-life (t½ = 68 min) that is particularly well suited for molecular imaging by positron emission tomography (PET). Methods have been developed to synthesize (68)Ga-labeled imaging agents possessing certain drawbacks, such as longer synthesis time because of a required final purification step, the use of organic solvents or concentrated hydrochloric acid (HCl). In our manuscript, we provide a detailed protocol for the use of an advantageous sodium chloride (NaCl)-based method for radiolabeling of chelator-modified peptides for molecular imaging. By working in a lead-shielded hot-cell system,(68)Ga(3+) of the generator eluate is trapped on a cation exchanger cartridge (100 mg, ∼8 mm long and 5 mm diameter) and then eluted with acidified 5 M NaCl solution directly into a sodium acetate-buffered solution containing a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) or DOTA-like chelator-modified peptide. The main advantages of this procedure are the high efficiency and the absence of organic solvents. It can be applied to a variety of peptides, which are stable in 1 M NaCl solution at a pH value of 3-4 during reaction. After labeling, neutralization, sterile filtration and quality control (instant thin-layer chromatography (iTLC), HPLC and pH), the radiopharmaceutical can be directly administered to patients, without determination of organic solvents, which reduces the overall synthesis-to-release time. This procedure has been adapted easily to automated synthesis modules, which leads to a rapid preparation of (68)Ga radiopharmaceuticals (12-16 min).
Pharmacology, Toxicology and Pharmaceutical Science
9
9%
Medicine and Dentistry
9
9%
Biochemistry, Genetics and Molecular Biology
8
8%
Engineering
6
6%
Other
12
12%
Unknown
29
29%
Attention Score in Context
Attention Score in Context
This research output has an Altmetric Attention Score of 4. This is our high-level measure of the quality and quantity of online attention that it has received. This Attention Score, as well as the ranking and number of research outputs shown below, was calculated when the research output was last mentioned on 31 March 2026.
All research outputs
#6,972,253
of 24,293,076 outputs
Outputs from Nature Protocols
#1,924
of 2,831 outputs
Outputs of similar age
#98,385
of 316,754 outputs
Outputs of similar age from Nature Protocols
#21
of 34 outputs
Altmetric has tracked 24,293,076 research outputs across all sources so far. This one has received more attention than most of these and is in the 69th percentile.
So far Altmetric has tracked 2,831 research outputs from this source. They typically receive a lot more attention than average, with a mean Attention Score of 16.2. This one is in the 30th percentile – i.e., 30% of its peers scored the same or lower than it.
Older research outputs will score higher simply because they've had more time to accumulate mentions. To account for age we can compare this Altmetric Attention Score to the 316,754 tracked outputs that were published within six weeks on either side of this one in any source. This one has gotten more attention than average, scoring higher than 67% of its contemporaries.
We're also able to compare this research output to 34 others from the same source and published within six weeks on either side of this one. This one is in the 41st percentile – i.e., 41% of its contemporaries scored the same or lower than it.
